Fastenal (FAST) 10-K6 Feb 202019 FY Annual reportFinancial data

Company Profile

Document And Entity Information

Document And Entity Information - USD ($)	12 Months Ended
Document And Entity Information - USD ($)	Dec. 31, 2019	Jan. 22, 2020	Jun. 28, 2019
Cover page.
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2019
Document Transition Report	false
Entity File Number	0-16125
Entity Registrant Name	FASTENAL CO
Entity Incorporation, State or Country Code	MN
Entity Tax Identification Number	41-0948415
Entity Address, Address Line One	2001 Theurer Boulevard
Entity Address, City or Town	Winona
Entity Address, State or Province	MN
Entity Address, Postal Zip Code	55987-1500
City Area Code	507
Local Phone Number	454-5374
Title of 12(b) Security	Common stock, par value $.01 per share
Trading Symbol	FAST
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 18,623,405,521
Entity Common Stock, Shares Outstanding		574,226,297
Entity Central Index Key	0000815556
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Amendment Flag	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 174.9	$ 167.2
Trade accounts receivable, net of allowance for doubtful accounts of $10.9 and $12.8, respectively	741.8	714.3
Inventories	1,366.4	1,278.7
Prepaid income taxes	16.7	9
Other current assets	157.4	147
Total current assets	2,457.2	2,316.2
Property and equipment, net	1,023.2	924.8
Operating lease right-of-use assets	243.2	0
Other assets	76.3	80.5
Total assets	3,799.9	3,321.5
Current liabilities:
Current portion of debt	3	3
Accounts payable	192.8	193.6
Accrued expenses	251.5	240.8
Current portion of operating lease liabilities	97.4	0
Total current liabilities	544.7	437.4
Long-term debt	342	497
Operating lease liabilities	148.2	0
Deferred income taxes	99.4	84.4
Commitments and contingencies (Notes 5, 8, 9, and 10)
Stockholders' equity:
Preferred stock: $0.01 par value, 5,000,000 shares authorized, no shares issued or outstanding	0	0
Common stock: $0.01 par value, 800,000,000 shares authorized, 574,128,911 and 571,803,838 shares issued and outstanding, respectively	2.9	2.9
Additional paid-in capital	67.2	3
Retained earnings	2,633.9	2,341.6
Accumulated other comprehensive loss	(38.4)	(44.8)
Total stockholders' equity	2,665.6	2,302.7
Total liabilities and stockholders' equity	$ 3,799.9	$ 3,321.5

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Trade accounts receivable, allowance for doubtful accounts	$ 10.9	$ 12.8
Preferred stock:
Par value (in dollars per share)	$ 0.01	$ 0.01
Authorized (in shares)	5,000,000	5,000,000
Issued (in shares)	0	0
Outstanding (in shares)	0	0
Common stock:
Par value (in dollars per share)	$ 0.01	$ 0.01
Authorized (in shares)	800,000,000	800,000,000
Issued (in shares)	574,128,911	571,803,838
Outstanding (in shares)	574,128,911	571,803,838

Consolidated Statements of Earn

Consolidated Statements of Earnings - USD ($) $ in Millions	12 Months Ended
Consolidated Statements of Earnings - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Net sales	$ 5,333.7	$ 4,965.1	$ 4,390.5
Cost of sales	2,818.3	2,566.2	2,226.9
Gross profit	2,515.4	2,398.9	2,163.6
Operating and administrative expenses	1,459.4	1,400.2	1,282.8
Gain on sale of property and equipment	(1.2)	(0.5)	(1)
Operating income	1,057.2	999.2	881.8
Interest income	0.4	0.4	0.4
Interest expense	(13.9)	(12.6)	(9.1)
Earnings before income taxes	1,043.7	987	873.1
Income tax expense	252.8	235.1	294.5
Net earnings	$ 790.9	$ 751.9	$ 578.6
Basic net earnings per share (in dollars per share)	$ 1.38	$ 1.31	$ 1
Diluted net earnings per share (in dollars per share)	$ 1.38	$ 1.31	$ 1
Basic weighted average shares outstanding (in shares)	573,202,152	573,933,834	576,416,870
Diluted weighted average shares outstanding (in shares)	574,441,628	574,325,528	576,685,466

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net earnings	$ 790.9	$ 751.9	$ 578.6
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments (net of tax of $0.0 in 2019, 2018, and 2017)	6.4	(19.7)	22.2
Comprehensive income	$ 797.3	$ 732.2	$ 600.8

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Foreign currency translation adjustments, tax	$ 0	$ 0	$ 0

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Millions	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated other comprehensive income (loss)
Balance at beginning of year at Dec. 31, 2016		$ 2.9	$ 37.4	$ 1,940.1	$ (47.3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock options exercised			9.5
Purchases of common stock			(43.6)	(39)
Stock-based compensation			5.2
Net earnings	$ 578.6			578.6
Dividends paid in cash				(369.1)
Other comprehensive income (loss)					22.2
Balance at end of year at Dec. 31, 2017	$ 2,096.9	2.9	8.5	2,110.6	(25.1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash dividends paid per share of common stock (in dollars per share)	$ 0.64
Stock options exercised			13.4
Purchases of common stock			(24)	(79)
Stock-based compensation			5.1
Net earnings	$ 751.9			751.9
Dividends paid in cash				(441.9)
Other comprehensive income (loss)					(19.7)
Balance at end of year at Dec. 31, 2018	$ 2,302.7	2.9	3	2,341.6	(44.8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash dividends paid per share of common stock (in dollars per share)	$ 0.77
Stock options exercised			58.5
Purchases of common stock			0	0
Stock-based compensation			5.7
Net earnings	$ 790.9			790.9
Dividends paid in cash				(498.6)
Other comprehensive income (loss)					6.4
Balance at end of year at Dec. 31, 2019	$ 2,665.6	$ 2.9	$ 67.2	$ 2,633.9	$ (38.4)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash dividends paid per share of common stock (in dollars per share)	$ 0.87

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net earnings	$ 790.9	$ 751.9	$ 578.6
Adjustments to reconcile net earnings to net cash provided by operating activities, net of acquisitions:
Depreciation of property and equipment	144.6	134.1	123.6
Gain on sale of property and equipment	(1.2)	(0.5)	(1)
Bad debt expense	5.5	8.1	8.2
Deferred income taxes	15	33.8	(30)
Stock-based compensation	5.7	5.1	5.2
Amortization of intangible assets	4.1	4.1	3.8
Changes in operating assets and liabilities, net of acquisitions:
Trade accounts receivable	(30.4)	(120.3)	(103.7)
Inventories	(84.4)	(193.3)	(76.3)
Other current assets	(10.4)	(28.9)	(15.6)
Accounts payable	(0.8)	46.1	36.3
Accrued expenses	10.7	46.8	37.6
Income taxes	(7.7)	(15.5)	19.4
Other	1.1	2.7	(0.9)
Net cash provided by operating activities	842.7	674.2	585.2
Cash flows from investing activities:
Purchases of property and equipment	(246.4)	(176.3)	(119.9)
Proceeds from sale of property and equipment	6.6	9.5	7.4
Cash paid for acquisitions	0	(3.7)	(58.7)
Other	0.1	(3.4)	(8.1)
Net cash used in investing activities	(239.7)	(173.9)	(179.3)
Cash flows from financing activities:
Proceeds from debt obligations	910	980	1,015
Payments against debt obligations	(1,065)	(895)	(980)
Proceeds from exercise of stock options	58.5	13.4	9.5
Purchases of common stock	0	(103)	(82.6)
Payments of dividends	(498.6)	(441.9)	(369.1)
Net cash used in financing activities	(595.1)	(446.5)	(407.2)
Effect of exchange rate changes on cash and cash equivalents	(0.2)	(3.5)	5.5
Net increase in cash and cash equivalents	7.7	50.3	4.2
Cash and cash equivalents at beginning of year	167.2	116.9	112.7
Cash and cash equivalents at end of year	174.9	167.2	116.9
Supplemental disclosure of cash flow information:
Cash paid for interest	13.9	12.6	8.7
Net cash paid for income taxes	$ 242.7	$ 215.3	$ 304.1

Business Overview and Summary o

Business Overview and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Business Overview and Summary of Significant Accounting Policies	Note 1. Business Overview and Summary of Significant Accounting Policies Business Overview Fastenal is a leader in the wholesale distribution of industrial and construction supplies operating a branch-based business (with an increasing number of Onsite locations). Collectively we refer to our branches and Onsite locations as in-market locations. We have over 3,200 in-market locations located primarily in North America. Principles of Consolidation The consolidated financial statements include the accounts of Fastenal Company and its subsidiaries (collectively referred to as 'Fastenal' or by terms such as 'we', 'our', or 'us'). All material intercompany balances and transactions have been eliminated in consolidation. Revenue Recognition Net sales include products and shipping and handling charges, net of estimates for product returns and any related sales incentives. Revenue is measured as the amount of consideration we expect to receive in exchange for transferring products. All revenue is recognized when we satisfy our performance obligations under the contract. We recognize revenue by transferring the promised products to the customer, with the majority of revenue recognized at the point in time the customer obtains control of the products. We recognize revenue for shipping and handling charges at the time the products are delivered to or picked up by the customer. We estimate product returns based on historical return rates. Using probability assessments, we estimate sales incentives expected to be paid over the term of the contract. The majority of our contracts have a single performance obligation and are short term in nature. Sales taxes and value added taxes in foreign jurisdictions that are collected from customers and remitted to governmental authorities are accounted for on a net basis and therefore are excluded from net sales. Accounts Receivable Credit is extended based upon an evaluation of the customer's financial condition. Accounts receivable are stated at their estimated net realizable value. The allowance for doubtful accounts is based on an analysis of customer accounts and our historical experience with accounts receivable write-offs. Foreign Currency Translation and Transactions The functional currency of our foreign operations is typically the applicable local currency. The functional currency is translated into United States dollars for balance sheet accounts, except retained earnings, using current exchange rates as of the balance sheet date, for retained earnings at historical exchange rates, and for revenue and expense accounts using a weighted average exchange rate during the applicable period. The translation adjustments are deferred as a separate component of stockholders' equity captioned accumulated other comprehensive income (loss). Gains or losses resulting from transactions denominated in foreign currencies are included in cost of sales or operating and administrative expenses. Cash and Cash Equivalents We consider all investments purchased with original maturities of three months or less to be cash equivalents. Inventories Inventories, consisting of finished goods merchandise held for resale, are stated at the lower of cost (first in, first out method) or net realizable value. We establish a reserve for excess, slow-moving, and obsolete inventory that is equal to the difference between the cost and estimated net realizable value for that inventory. These reserves are based on a review and comparison of the current inventory levels to projected and historical sales of inventory. Property and Equipment Property and equipment are stated at cost. Depreciation on property and equipment is provided for using the straight-line method over the anticipated economic useful lives of the related property. Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If circumstances require a long-lived asset or asset group be tested for possible impairment, we first compare undiscounted cash flows expected to be generated by the asset or asset group to its carrying value. If the carrying value of the long-lived asset or asset group is not recoverable on an undiscounted cash flow basis, an impairment is recognized to the extent the carrying value exceeds its fair value. Fair value is determined through various valuation techniques including discounted cash flow models, quoted market values, and third-party independent appraisals, as considered necessary. There were no impairments recorded during any of the three years reported in these consolidated financial statements. Leases We determine if an arrangement contains a lease at inception. Operating leases are included in our operating lease right-of-use ('ROU') assets, the current portion of operating lease liabilities, and the operating lease liabilities in our Consolidated Balance Sheets. The ROU assets represent our right to control the use of an underlying asset for the lease term, and lease liabilities represent our obligation to make lease payments arising from the lease. Operating lease ROU assets and lease liabilities are recognized at commencement date based on the present value of lease payments over the lease term. The operating lease ROU assets also include any prepaid lease payments made and exclude lease incentives. Lease expense is recognized on a straight-line basis over the lease term. Many of our leases include both lease (e.g., fixed payments including rent, taxes, and insurance costs) and nonlease components (e.g., common-area or other maintenance costs) which are accounted for as a single lease component as we have elected the practical expedient to group lease and nonlease components for all leases. Our pick-up truck leases typically have a non-cancelable lease term of less than one year and therefore, we have elected the practical expedient to exclude these short-term leases from our ROU assets and lease liabilities. Most leases include one or more options to renew. The exercise of lease renewal options is typically at our sole discretion; therefore, the majority of renewals to extend the lease terms are not included in our ROU assets and lease liabilities as they are not reasonably certain of exercise. We regularly evaluate the renewal options and when they are reasonably certain of exercise, we include the renewal period in our lease term. As most of our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at the lease commencement date in determining the present value of the lease payments. We have a centrally managed treasury function; therefore, based on the applicable lease terms and the current economic environment, we apply a portfolio approach for determining the incremental borrowing rate. Other Long-Lived Assets Other assets consist of prepaid deposits, goodwill, and other definite-lived intangible assets. Goodwill represents the excess of the purchase price over the fair value of net assets acquired. Goodwill is reviewed for impairment annually. The identifiable intangible assets are amortized on a straight-line basis over their estimated life. Accounting Estimates The preparation of the consolidated financial statements in conformity with U.S. generally accepted accounting principles ('GAAP') requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities, revenues and expenses, and the disclosure of contingent liabilities. Actual results could differ from those estimates. Insurance Reserves We are self-insured for certain losses relating to workers' compensation, automobile, health, and general liability costs. Specific stop-loss coverage is provided for catastrophic claims in order to limit exposure to significant claims. Self-insurance liabilities are based on our estimate of reported claims and claims incurred but not yet reported. Product Warranties We offer a basic limited warranty for certain of our products. The specific terms and conditions of those warranties vary depending upon the product sold. We typically recoup these costs through product warranties we hold with the original equipment manufacturers. Our warranty expense has historically been minimal. Stock-Based Compensation We estimate the value of stock option grants using a Black-Scholes valuation model. Stock-based compensation expense is recognized on a straight-line basis over the vesting period. Our stock-based compensation expense is recorded in operating and administrative expenses. Income Taxes We account for income taxes under the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. We recognize the effect of income tax positions only if those positions are more likely than not to be sustained. Recognized income tax positions are measured at the largest amount that is greater than 50% likely of being realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs. We record interest and penalties related to unrecognized tax benefits in income tax expense. Earnings Per Share Basic net earnings per share is calculated using net earnings available to common stockholders divided by the weighted average number of shares of common stock outstanding during the year. Diluted net earnings per share is similar to basic net earnings per share except that the weighted average number of shares of common stock outstanding includes the incremental shares assumed to be issued upon the exercise of stock options considered to be 'in-the-money' (i.e., when the market price of our stock is greater than the exercise price of our outstanding stock options). Segment Reporting We have determined that for our North American operations we meet the aggregation criteria outlined in the accounting standards as our various operations have similar (1) economic characteristics, (2) products and services, (3) customers, (4) distribution channels, and (5) regulatory environments. Considering the insignificance of our operations outside of North America, we report as a single business segment. Stock Split On April 17, 2019, the board of directors approved a two -for-one stock split of the company's outstanding common stock. Holders of the company's common stock, par value $0.01 per share, at the close of business on May 2, 2019, received one additional share of common stock for every share of common stock they owned. The stock split took effect at the close of business on May 22, 2019. All historical common stock share and per share information for all periods presented in the accompanying consolidated financial statements and notes thereto have been retroactively adjusted to reflect the stock split. Recently Adopted Accounting Pronouncements Effective January 1, 2019, we adopted the Financial Accounting Standards Board ('FASB') Accounting Standards Update ('ASU') 2016-02, Leases (Topic 842) , which requires the recognition of lease assets and lease liabilities by lessees for those leases classified as operating leases under previous guidance. The original guidance required application on a modified retrospective basis with the earliest period presented. In August 2018, the FASB issued ASU 2018-11, Targeted Improvements to ASC 842 , which included an option to not restate comparative periods in transition and elect to use the effective date of ASC 842, Leases , as the date of initial application of transition, which we elected. As a result of the adoption of ASC 842 on January 1, 2019, we recorded both operating lease ROU assets of $227.5 and lease liabilities of $228.3 . The adoption of ASC 842 had an immaterial impact on our Consolidated Statement of Earnings and Consolidated Statement of Cash Flows for the year ended December 31, 2019. In addition, we elected the package of practical expedients permitted under the transition guidance within the new standard which allowed us to carry forward the historical lease classification. Recently Issued Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13, Measurement of Credit Losses on Financial Instruments , which changes the way entities recognize impairment of most financial assets. This update is effective for periods beginning after December 15, 2019. Short-term and long-term financial assets, as defined by the standard, are impacted by immediate recognition of estimated credit losses in the financial statements, reflecting the net amount expected to be collected. We have evaluated the requirements of this standard on our financial assets and have concluded that the adoption of this ASU, beginning January 1, 2020, will have an immaterial impact on our consolidated financial statements.

Revenue

Revenue	12 Months Ended
Revenue	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Revenue	Note 2. Revenue Disaggregation of Revenue The accounting policies of the operations in the various geographic areas are the same as those described in the summary of significant accounting policies. Revenues are attributed to countries based on the selling location from which the sale occurred. In each of the years presented in the tables below, no single customer represented 5% or more of our consolidated net sales. Our revenues related to the following geographic areas were as follows for the periods ended December 31: Twelve-month period 2019 2018 2017 United States $ 4,568.9 4,285.5 3,842.9 Canada and Mexico 606.8 530.8 432.3 North America 5,175.7 4,816.3 4,275.2 All other foreign countries 158.0 148.8 115.3 Total revenues $ 5,333.7 4,965.1 4,390.5 The percentages of our sales by end market were as follows for the periods ended December 31: Twelve-month period 2019 2018 2017 Manufacturing 67.5 % 66.7 % 66.5 % Non-residential construction 12.9 % 13.1 % 13.0 % Other 19.6 % 20.2 % 20.5 % 100.0 % 100.0 % 100.0 % The percentages of our sales by product line were as follows for the periods ended December 31 (1) : Twelve-month Period Type Introduced 2019 2018 2017 Fasteners (2) 1967 34.2 % 34.9 % 35.6 % Tools 1993 9.9 % 10.0 % 10.1 % Cutting tools 1996 5.7 % 5.7 % 5.8 % Hydraulics & pneumatics 1996 6.8 % 6.8 % 6.8 % Material handling 1996 5.9 % 5.8 % 5.9 % Janitorial supplies 1996 7.8 % 7.6 % 7.3 % Electrical supplies 1997 4.7 % 4.7 % 4.9 % Welding supplies 1997 4.2 % 4.1 % 4.2 % Safety supplies 1999 17.9 % 17.2 % 16.3 % Other 2.9 % 3.2 % 3.1 % 100.0 % 100.0 % 100.0 % (1) In 2018, we reclassified certain product category designations and have conformed the prior period percentages to the current year presentation. (2) The fastener product line represents fasteners and miscellaneous supplies.

Long-Lived Assets

Long-Lived Assets	12 Months Ended
Long-Lived Assets	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Long-Lived Assets	Note 3. Long-Lived Assets The accounting policies of the operations in the various geographic areas are the same as those described in the summary of significant accounting policies. Long-lived assets consist of net property and equipment, deposits, goodwill, and other net intangibles. Property and equipment at year end consisted of the following: Depreciable Life in Years 2019 2018 Land — $ 41.8 36.3 Buildings and improvements 15 to 40 423.7 323.1 Automated distribution and warehouse equipment 5 to 30 244.5 229.1 Shelving, industrial vending, and equipment 3 to 10 1,036.2 927.6 Transportation equipment 3 to 5 88.7 77.9 Construction in progress — 132.0 152.2 1,966.9 1,746.2 Less accumulated depreciation (943.7 ) (821.4 ) Property and equipment, net $ 1,023.2 924.8 Our long-lived assets related to the following geographic areas: 2019 2018 2017 United States $ 1,238.4 947.7 919.5 Canada and Mexico 72.2 43.0 42.8 North America 1,310.6 990.7 962.3 All other foreign countries 32.1 14.6 12.5 Total long-lived assets $ 1,342.7 1,005.3 974.8

Accrued Expenses

Accrued Expenses	12 Months Ended
Accrued Expenses	Dec. 31, 2019
Payables and Accruals [Abstract]
Accrued Expenses	Note 4. Accrued Expenses Accrued expenses at year end consisted of the following: 2019 2018 Employee payroll and related taxes $ 28.7 27.6 Employee bonuses and commissions 17.9 22.8 Profit sharing contribution 13.8 13.0 Insurance reserves 41.1 37.6 Indirect taxes 67.4 63.6 Customer promotions and marketing 52.2 50.9 Other 30.4 25.3 Accrued expenses $ 251.5 240.8

Stockholders' Equity

Stockholders' Equity	12 Months Ended
Stockholders' Equity	Dec. 31, 2019
Stockholders' Equity Note [Abstract]
Stockholders' Equity	Note 5. Stockholders' Equity Dividends On January 16, 2020 , our board of directors declared a quarterly dividend of $0.25 per share of common stock to be paid in cash on February 28, 2020 to shareholders of record at the close of business on January 31, 2020 . We paid aggregate annual dividends per share of $0.87 , $0.77 , and $0.64 in 2019 , 2018 , and 2017 , respectively. Stock Options Effective January 2, 2020, the compensation committee of our board of directors granted to our employees options to purchase a total of 877,299 shares of our common stock at an exercise strike price of $38.00 per share. The closing stock price on the effective date of the grant was $37.23 per share. On the same date, certain of our non-employee directors elected to forgo all or a portion of the 2020 annual cash retainer in exchange for options to acquire a total of 24,964 shares of our common stock at an exercise price of $38.00 per share. The following tables summarize the details of options granted under our stock option plans that were still outstanding as of December 31, 2019, and the assumptions used to value those grants. All such grants were effective at the close of business on the date of grant. Options Granted Option Exercise (Strike) Price Closing Stock Price on Date of Grant December 31, 2019 Date of Grant Options Outstanding Options Exercisable January 2, 2019 1,316,924 $ 26.00 $ 25.705 1,279,842 29,010 January 2, 2018 1,087,936 $ 27.50 $ 27.270 1,019,440 42,370 January 3, 2017 1,529,578 $ 23.50 $ 23.475 1,197,606 332,132 April 19, 2016 1,690,880 $ 23.00 $ 22.870 1,220,524 447,166 April 21, 2015 1,786,440 $ 21.00 $ 20.630 833,593 444,589 April 22, 2014 1,910,000 $ 28.00 $ 25.265 599,128 357,268 April 16, 2013 410,000 $ 27.00 $ 24.625 97,472 58,722 April 17, 2012 2,470,000 $ 27.00 $ 24.505 547,112 440,310 April 19, 2011 820,000 $ 17.50 $ 15.890 12,500 12,500 Total 13,021,758 6,807,217 2,164,067 Date of Grant Risk-free Interest Rate Expected Life of Option in Years Expected Dividend Yield Expected Stock Volatility Estimated Fair Value of Stock Option January 2, 2019 2.5 % 5.00 2.9 % 23.96 % $ 4.40 January 2, 2018 2.2 % 5.00 2.3 % 23.45 % $ 5.02 January 3, 2017 1.9 % 5.00 2.6 % 24.49 % $ 4.20 April 19, 2016 1.3 % 5.00 2.6 % 26.34 % $ 4.09 April 21, 2015 1.3 % 5.00 2.7 % 26.84 % $ 3.68 April 22, 2014 1.8 % 5.00 2.0 % 28.55 % $ 4.79 April 16, 2013 0.7 % 5.00 1.6 % 37.42 % $ 6.33 April 17, 2012 0.9 % 5.00 1.4 % 39.25 % $ 6.85 April 19, 2011 2.1 % 5.00 1.6 % 39.33 % $ 5.60 All of the options in the tables above vest and become exercisable over a period of up to eight years . Generally, each option will terminate approximately nine years after the grant date. The fair value of each share-based option is estimated on the date of grant using a Black-Scholes valuation method that uses the assumptions listed above. The risk-free interest rate is based on the U.S. Treasury rate over the expected life of the option at the time of grant. The expected life is the average length of time over which we expect the employee groups will exercise their options, which is based on historical experience with similar grants. The dividend yield is estimated over the expected life of the option based on our current dividend payout, historical dividends paid, and expected future cash dividends. Expected stock volatilities are based on the movement of our stock price over the most recent historical period equivalent to the expected life of the option. A summary of activities under our stock option plans consisted of the following: Options Outstanding Exercise Price (1) Remaining Life (2) Outstanding as of January 1, 2019 7,999,264 $ 24.765 5.61 Granted 1,316,924 $ 26.000 9.00 Exercised (2,325,073 ) $ 25.150 Cancelled/forfeited (183,898 ) $ 24.630 Outstanding as of December 31, 2019 6,807,217 $ 24.890 6.09 Exercisable as of December 31, 2019 2,164,067 $ 24.510 4.30 Options Outstanding Exercise (1) Remaining Life (2) Outstanding as of January 1, 2018 7,897,816 $ 24.140 5.89 Granted 1,087,936 $ 27.500 9.00 Exercised (620,766 ) $ 21.655 Cancelled/forfeited (365,722 ) $ 24.430 Outstanding as of December 31, 2018 7,999,264 $ 24.765 5.61 Exercisable as of December 31, 2018 3,108,756 $ 25.530 3.69 (1) Weighted average exercise price. (2) Weighted average remaining contractual life in years. The total intrinsic value of stock options exercised during the years ended December 31, 2019 , 2018 , and 2017 was $20.2 , $4.2 , and $6.9 , respectively. The intrinsic value represents the difference between the exercise price and fair value of the underlying shares at the date of exercise. At December 31, 2019 , there was $13.1 of total unrecognized stock-based compensation expense related to outstanding unvested stock options granted under the employee stock option plan. This expense is expected to be recognized over a weighted average period of 3.82 years. Any future change in estimated forfeitures will impact this amount. The total grant date fair value of stock options vested under our employee stock option plan during 2019 , 2018 , and 2017 was $5.9 , $5.3 , and $4.2 , respectively. Total stock-based compensation expense related to our employee stock option plan was $5.7 , $5.1 , and $5.2 for 2019 , 2018 , and 2017 , respectively. Shares Outstanding Shares of common stock outstanding were as follows: 2019 2018 2017 Balance at beginning of year 571,803,838 575,183,072 578,323,848 Stock options exercised 2,325,073 620,766 659,224 Purchases of common stock — (4,000,000 ) (3,800,000 ) Balance at end of year 574,128,911 571,803,838 575,183,072 Earnings Per Share The following tables present a reconciliation of the denominators used in the computation of basic and diluted earnings per share and a summary of the options to purchase shares of common stock which were excluded from the diluted earnings calculation because they were anti-dilutive: Reconciliation 2019 2018 2017 Basic weighted average shares outstanding 573,202,152 573,933,834 576,416,870 Weighted shares assumed upon exercise of stock options 1,239,476 391,694 268,596 Diluted weighted average shares outstanding 574,441,628 574,325,528 576,685,466 Summary of Anti-dilutive Options Excluded 2019 2018 2017 Options to purchase shares of common stock — 3,159,514 7,048,802 Weighted average exercise prices of options $ — 27.510 24.925 Any dilutive impact summarized above related to periods when the average market price of our stock exceeded the exercise price of the potentially dilutive stock options then outstanding.

Retirement Savings Plan

Retirement Savings Plan	12 Months Ended
Retirement Savings Plan	Dec. 31, 2019
Defined Contribution Plan [Abstract]
Retirement Savings Plan	Note 6. Retirement Savings Plan The Fastenal Company and Subsidiaries 401(k) and Employee Stock Ownership Plan covers all of our employees in the United States. Our employees in Canada may participate in a Registered Retirement Savings Plan. The general purpose of both of these plans is to provide additional financial security during retirement by providing employees with an incentive to make regular savings contributions. In addition to the participation of our employees, we make annual profit sharing contributions based on an established formula. The expense recorded under this profit sharing formula was approximately $13.8 , $13.0 , and $10.6 for 2019 , 2018 , and 2017 , respectively.

Income Taxes

Income Taxes	12 Months Ended
Income Taxes	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Note 7. Income Taxes Earnings before income taxes were derived from the following sources: 2019 2018 2017 Domestic $ 977.6 905.0 809.4 Foreign 66.1 82.0 63.7 Earnings before income taxes $ 1,043.7 987.0 873.1 Components of income tax expense (benefit) were as follows: 2019: Current Deferred Total Federal $ 177.4 11.3 188.7 State 41.6 0.2 41.8 Foreign 22.1 0.2 22.3 Income tax expense $ 241.1 11.7 252.8 2018: Current Deferred Total Federal $ 143.8 27.4 171.2 State 38.8 0.2 39.0 Foreign 24.1 0.8 24.9 Income tax expense $ 206.7 28.4 235.1 2017: Current Deferred Total Federal $ 270.6 (33.1 ) 237.5 State 33.2 3.3 36.5 Foreign 20.5 (0.0 ) 20.5 Income tax expense $ 324.3 (29.8 ) 294.5 Income tax expense in the accompanying consolidated financial statements differed from the expected expense as follows: 2019 2018 2017 U.S. federal statutory income tax rate 21.0 % 21.0 % 35.0 % U.S. federal income tax expense at statutory rate $ 219.2 207.3 305.6 Increase (decrease) attributed to: State income taxes, net of federal benefit 32.8 30.2 21.5 Transition tax — 1.2 6.5 Remeasurement of deferred taxes for Tax Act — (11.5 ) (30.8 ) Other, net 0.8 7.9 (8.3 ) Total income tax expense $ 252.8 235.1 294.5 Effective income tax rate 24.2 % 23.8 % 33.7 % The tax effects of temporary differences that give rise to deferred income tax assets and liabilities at year end consisted of the following: 2019 2018 Deferred income tax assets (liabilities): Inventory costing and valuation methods $ 4.3 4.2 Allowance for doubtful accounts 2.7 3.2 Insurance reserves 9.1 8.1 Customer promotions 1.9 1.9 Stock-based compensation 3.9 5.6 Operating lease liabilities 62.5 — Federal and state benefit of uncertain tax positions 0.8 0.8 Foreign net operating loss and credit carryforwards 3.2 3.2 Foreign valuation allowances (2.8 ) (2.7 ) Other, net (0.0 ) 1.3 Total deferred income tax assets 85.6 25.6 Property and equipment (114.7 ) (104.7 ) Operating lease ROU assets (61.7 ) — Total deferred income tax liabilities (176.4 ) (104.7 ) Deferred income tax liabilities $ (90.8 ) (79.1 ) A reconciliation of the beginning and ending amount of total gross unrecognized tax benefits was as follows: 2019 2018 Balance at beginning of year: $ 5.3 4.4 Increase related to prior year tax positions 0.2 1.8 Decrease related to prior year tax positions (0.2 ) (0.6 ) Increase related to current year tax positions 4.7 0.7 Decrease related to statute of limitation lapses (1.4 ) (0.9 ) Settlements 0.0 (0.1 ) Balance at end of year: $ 8.6 5.3 Included in the liability for gross unrecognized tax benefits is an immaterial amount for interest and penalties, both of which we classify as a component of income tax expense. The amount of gross unrecognized tax benefits that would favorably impact the effective tax rate, if recognized, is not material. We do not anticipate significant changes in total unrecognized tax benefits during the next twelve months. The 2019 and 2018 liability is included in deferred income taxes in the Consolidated Balance Sheets. We file income tax returns in the United States federal jurisdiction, all states, and various local and foreign jurisdictions. We are no longer subject to income tax examinations by taxing authorities for taxable years before 2016 in the case of United States federal examinations, and with limited exception, before 2014 in the case of foreign, state, and local examinations. On December 22, 2017, the Tax Act was signed into law. The Tax Act made broad and complex changes to the U.S. tax code which include: a lowering of the U.S. federal corporate income tax rate from 35% to 21% effective January 1, 2018, accelerated expensing of qualified capital investments for a specific period, and a transition from a worldwide to a territorial tax system which requires companies to pay a one-time transition tax on certain unrepatriated earnings from foreign subsidiaries. ASC 740 requires a company to record the effects of a tax law change in the period of enactment which, for us, was fiscal 2017. ASU 2018-05 provides guidance on the application of the Tax Act which includes allowing a company to record a provisional amount during the measurement period for the impacts when the necessary information is not available, prepared, or analyzed in reasonable detail to complete its accounting for the change in the tax law. The measurement period ends when the company has obtained, prepared and analyzed the information necessary to finalize its accounting, but cannot extend beyond one year. We recorded income tax expense of $235.1 in 2018, or 23.8% of earnings before income taxes. The effective income tax rate was significantly impacted by the following two items: (1) The lower corporate tax rate provided by the Tax Act resulted in a lower tax rate beginning in the first quarter of 2018. The effective income tax rate includes the immaterial impact of the U.S. tax rate on certain offshore earnings referred to as GILTI, a new deduction for FDII, and the new alternative U.S. tax on certain BEAT payments from a U.S. company to any foreign related party. (2) Discrete income tax items to adjust our transition tax liability, reflect the impacts of accelerating depreciation for certain physical assets, and remeasure the impact of the U.S. tax rate on certain inter-company transactions. These discrete items resulted in approximately $7.1 of income tax benefit during 2018. The accounting for the income tax effects of the Tax Act was complete as of December 31, 2018. In general, it is our practice and intention to permanently reinvest the earnings of our foreign subsidiaries and repatriate earnings only when the tax impact is zero or very minimal and that position has not changed subsequent to the one-time transition tax under the Tax Act. Accordingly, no deferred taxes have been provided for withholding taxes or other taxes that would result upon repatriation of our approximately $288.1 of undistributed earnings from foreign subsidiaries to the U.S. as those earnings continue to be permanently reinvested.

Operating Leases

Operating Leases	12 Months Ended
Operating Leases	Dec. 31, 2019
Leases [Abstract]
Operating Leases	Note 8. Operating Leases We lease space under non-cancelable operating leases for several distribution centers, several manufacturing locations, and certain branch locations. These leases do not have significant rent escalation holidays, concessions, leasehold improvement incentives, or other build-out clauses. Further, the leases do not contain contingent rent provisions. We also lease certain semi-tractors, pick-up trucks, and computer equipment under operating leases. Certain operating leases for pick-up trucks contain residual value guarantee provisions which would generally become due at the expiration of the operating lease agreement if the fair value of the leased vehicles is less than the guaranteed residual value. The aggregate residual value guarantee related to these leases was approximately $90.0 . We believe the likelihood of funding the guarantee obligation under any provision of the operating lease agreements is remote. The cost components of our operating leases were as follows for the period ended December 31, 2019: Twelve-month Period Leased Facilities and Equipment Leased Vehicles Total Operating lease cost $ 104.0 14.1 118.1 Variable lease cost 10.0 1.9 11.9 Short-term lease cost — 27.4 27.4 Total $ 114.0 43.4 157.4 Variable lease costs are excluded from ROU assets and lease liabilities and consist primarily of taxes, insurance, and common area or other maintenance costs for our leased facilities and equipment which are paid based on actual costs incurred by the lessor as well as variable mileage costs related to our leased vehicles. Maturities of our lease liabilities for all operating leases are as follows as of December 31, 2019: Leased Facilities and Equipment Leased Vehicles Total 2020 $ 88.3 12.7 101.0 2021 63.2 8.5 71.7 2022 39.5 6.0 45.5 2023 22.5 2.9 25.4 2024 10.0 0.1 10.1 2025 and thereafter 3.7 — 3.7 Total lease payments $ 227.2 30.2 257.4 Less: Imputed interest (10.8 ) (1.0 ) (11.8 ) Present value of lease liabilities $ 216.4 29.2 245.6 The weighted average remaining lease terms and discount rates for all of our operating leases were as follows as of December 31, 2019: Remaining lease term and discount rate: December 31, 2019 Weighted average remaining lease term (years) Leased facilities and equipment 3.26 Leased vehicles 2.89 Weighted average discount rate Lease facilities and equipment 3.18% Leased vehicles 2.70% Supplemental cash flow information related to our operating leases was as follows for the period ended December 31, 2019: Twelve-month Period Cash paid for amounts included in the measurement of lease liabilities: Operating cash outflow from operating leases $ 117.2 Leased assets obtained in exchange for new operating lease liabilities 116.1

Debt Commitments

Debt Commitments	12 Months Ended
Debt Commitments	Dec. 31, 2019
Debt Disclosure [Abstract]
Debt Commitments	Note 9. Debt Commitments Credit Facility, Notes Payable, and Commitments Debt obligations and letters of credit outstanding at year end consisted of the following: 2019 2018 Outstanding loans under unsecured revolving credit facility $ 210.0 365.0 2.00% Senior unsecured promissory note payable 40.0 40.0 2.45% Senior unsecured promissory note payable 35.0 35.0 3.22% Senior unsecured promissory note payable 60.0 60.0 Total debt 345.0 500.0 Less: Current portion of debt (3.0 ) (3.0 ) Long-term debt $ 342.0 497.0 Outstanding letters of credit under unsecured revolving credit facility - contingent obligation $ 36.3 36.3 Unsecured Revolving Credit Facility We have a $700.0 committed unsecured revolving credit facility ('Credit Facility'). The Credit Facility includes a committed letter of credit subfacility of $55.0 . The commitments under the Credit Facility will expire (and any borrowings outstanding under the Credit Facility will become due and payable) on November 30, 2023 . In the next twelve months, we have the ability and intent to repay a portion of the outstanding loans using cash; therefore, we have classified this portion as a current liability. The Credit Facility contains certain financial and other covenants, and our right to borrow under the Credit Facility is conditioned upon, among other things, our compliance with these covenants. We are currently in compliance with these covenants. Borrowings under the Credit Facility generally bear interest at a rate per annum equal to the London Interbank Offered Rate ('LIBOR') for interest periods of various lengths selected by us, plus 0.95% . Based on the interest periods we have chosen, our weighted per annum interest rate at December 31, 2019 was approximately 2.7% . We pay a commitment fee for the unused portion of the Credit Facility. This fee is either 0.10% or 0.125% per annum based on our usage of the Credit Facility. Senior Unsecured Promissory Notes Payable We have issued senior unsecured promissory notes under our master note agreement (the 'Master Note Agreement') in the aggregate principal amount of $135.0 . Our aggregate borrowing capacity under the Master Note Agreement is $600.0 ; however, none of the institutional investors party to that agreement are committed to purchase notes thereunder. The notes currently issued under our Master Note Agreement consist of three series. The first is in an aggregate principal amount of $40.0 , bears interest at a fixed rate of 2.00% per annum, and is due and payable on July 20, 2021. The second is in an aggregate principal amount of $35.0 , bears interest at a fixed rate of 2.45% per annum, and is due and payable on July 20, 2022. The third is in an aggregate principal amount of $60.0 , bears interest at a fixed rate of 3.22% per annum, and is due and payable on March 1, 2024. There is no amortization of these notes prior to their maturity date and interest is payable quarterly.

Legal Contingencies

Legal Contingencies	12 Months Ended
Legal Contingencies	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Legal Contingencies	Note 10. Legal Contingencies We are involved in certain legal actions. The outcomes of these legal actions are not within our complete control and may not be known for prolonged periods of time. In some actions, the claimants seek damages, as well as other relief, that could require significant expenditures or result in lost revenues. We record a liability for these legal actions when a loss is known or considered probable and the amount can be reasonably estimated. If the reasonable estimate of a known or probable loss is a range, and no amount within the range is a better estimate than any other, the minimum amount of the range is accrued. If a loss is reasonably possible but not known or probable, and can be reasonably estimated, the estimated loss or range of loss is disclosed. In most cases, significant judgment is required to estimate the amount and timing of a loss to be recorded. As of December 31, 2019 , there were no litigation matters that we consider to be probable or reasonably possible to have a material adverse outcome.

Subsequent Events

Subsequent Events	12 Months Ended
Subsequent Events	Dec. 31, 2019
Subsequent Events [Abstract]
Subsequent Events	Note 11. Subsequent Events We evaluated all subsequent event activity and concluded that no subsequent events have occurred that would require recognition in the consolidated financial statements or disclosure in the Notes to Consolidated Financial Statements, with the exception of the dividend declaration and stock option activities disclosed in Note 5.

Selected Quarterly Financial Da

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
Selected Quarterly Financial Data (Unaudited)	Dec. 31, 2019
Selected Quarterly Financial Information [Abstract]
Selected Quarterly Financial Data (Unaudited)	Note 12. Selected Quarterly Financial Data (Unaudited) (Amounts in millions except per share information) 2019: Net Sales Gross Profit Pre-tax Earnings Net Earnings Basic Net (1) Diluted Net Earnings per Share (1) First quarter $ 1,309.3 624.7 257.5 194.1 0.34 0.34 Second quarter 1,368.4 641.2 271.4 204.6 0.36 0.36 Third quarter 1,379.1 651.1 278.4 213.5 0.37 0.37 Fourth quarter 1,276.9 598.4 236.4 178.7 0.31 0.31 Total $ 5,333.7 2,515.4 1,043.7 790.9 1.38 1.38 2018: Net Sales Gross Profit Pre-tax Earnings Net Earnings Basic Net (1) Diluted Net Earnings per Share (1) First quarter $ 1,185.8 577.6 231.9 174.3 0.30 0.30 Second quarter 1,267.9 617.7 265.9 211.2 0.37 0.37 Third quarter 1,279.8 615.8 259.4 197.6 0.34 0.34 Fourth quarter 1,231.6 587.8 229.8 168.8 0.29 0.29 Total $ 4,965.1 2,398.9 987.0 751.9 1.31 1.31 (1) Amounts may not foot due to rounding difference.

Schedule II-Valuation and Quali

Schedule II-Valuation and Qualifying Accounts	12 Months Ended
Schedule II-Valuation and Qualifying Accounts	Dec. 31, 2019
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Schedule II-Valuation and Qualifying Accounts	Schedule II—Valuation and Qualifying Accounts Years ended December 31, 2019 , 2018 , and 2017 (Amounts in millions) Description Balance at Beginning of Year "Additions" Charged to Costs and Expenses "Other" Additions (Deductions) "Less" Deductions Balance at End of Year Year ended December 31, 2019 Allowance for doubtful accounts $ 12.8 5.5 — 7.4 10.9 Insurance reserves $ 37.6 69.7 (1) — 66.2 (2) 41.1 Year ended December 31, 2018 Allowance for doubtful accounts $ 11.9 8.1 — 7.2 12.8 Insurance reserves $ 39.0 66.9 (1) — 68.3 (2) 37.6 Year ended December 31, 2017 Allowance for doubtful accounts $ 11.2 8.2 — 7.5 11.9 Insurance reserves $ 34.6 68.2 (1) — 63.8 (2) 39.0 (1) Includes costs and expenses incurred for premiums and claims related to health and general insurance. (2) Includes costs and expenses paid for premiums and claims related to health and general insurance. See accompanying Report of Independent Registered Public Accounting Firm incorporated herein by reference.

Business Overview and Summary_2

Business Overview and Summary of Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Principles of Consolidation	The consolidated financial statements include the accounts of Fastenal Company and its subsidiaries (collectively referred to as 'Fastenal' or by terms such as 'we', 'our', or 'us'). All material intercompany balances and transactions have been eliminated in consolidation.
Revenue Recognition	Net sales include products and shipping and handling charges, net of estimates for product returns and any related sales incentives. Revenue is measured as the amount of consideration we expect to receive in exchange for transferring products. All revenue is recognized when we satisfy our performance obligations under the contract. We recognize revenue by transferring the promised products to the customer, with the majority of revenue recognized at the point in time the customer obtains control of the products. We recognize revenue for shipping and handling charges at the time the products are delivered to or picked up by the customer. We estimate product returns based on historical return rates. Using probability assessments, we estimate sales incentives expected to be paid over the term of the contract. The majority of our contracts have a single performance obligation and are short term in nature. Sales taxes and value added taxes in foreign jurisdictions that are collected from customers and remitted to governmental authorities are accounted for on a net basis and therefore are excluded from net sales.
Accounts Receivable	Credit is extended based upon an evaluation of the customer's financial condition. Accounts receivable are stated at their estimated net realizable value. The allowance for doubtful accounts is based on an analysis of customer accounts and our historical experience with accounts receivable write-offs.
Foreign Currency Translation and Transactions	The functional currency of our foreign operations is typically the applicable local currency. The functional currency is translated into United States dollars for balance sheet accounts, except retained earnings, using current exchange rates as of the balance sheet date, for retained earnings at historical exchange rates, and for revenue and expense accounts using a weighted average exchange rate during the applicable period. The translation adjustments are deferred as a separate component of stockholders' equity captioned accumulated other comprehensive income (loss). Gains or losses resulting from transactions denominated in foreign currencies are included in cost of sales or operating and administrative expenses.
Cash and Cash Equivalents	We consider all investments purchased with original maturities of three months or less to be cash equivalents.
Inventories	Inventories, consisting of finished goods merchandise held for resale, are stated at the lower of cost (first in, first out method) or net realizable value. We establish a reserve for excess, slow-moving, and obsolete inventory that is equal to the difference between the cost and estimated net realizable value for that inventory. These reserves are based on a review and comparison of the current inventory levels to projected and historical sales of inventory.
Property and Equipment	Property and equipment are stated at cost. Depreciation on property and equipment is provided for using the straight-line method over the anticipated economic useful lives of the related property. Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If circumstances require a long-lived asset or asset group be tested for possible impairment, we first compare undiscounted cash flows expected to be generated by the asset or asset group to its carrying value. If the carrying value of the long-lived asset or
Leases	We determine if an arrangement contains a lease at inception. Operating leases are included in our operating lease right-of-use ('ROU') assets, the current portion of operating lease liabilities, and the operating lease liabilities in our Consolidated Balance Sheets. The ROU assets represent our right to control the use of an underlying asset for the lease term, and lease liabilities represent our obligation to make lease payments arising from the lease. Operating lease ROU assets and lease liabilities are recognized at commencement date based on the present value of lease payments over the lease term. The operating lease ROU assets also include any prepaid lease payments made and exclude lease incentives. Lease expense is recognized on a straight-line basis over the lease term. Many of our leases include both lease (e.g., fixed payments including rent, taxes, and insurance costs) and nonlease components (e.g., common-area or other maintenance costs) which are accounted for as a single lease component as we have elected the practical expedient to group lease and nonlease components for all leases. Our pick-up truck leases typically have a non-cancelable lease term of less than one year and therefore, we have elected the practical expedient to exclude these short-term leases from our ROU assets and lease liabilities. Most leases include one or more options to renew. The exercise of lease renewal options is typically at our sole discretion; therefore, the majority of renewals to extend the lease terms are not included in our ROU assets and lease liabilities as they are not reasonably certain of exercise. We regularly evaluate the renewal options and when they are reasonably certain of exercise, we include the renewal period in our lease term. As most of our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at the lease commencement date in determining the present value of the lease payments. We have a centrally managed treasury function; therefore, based on the applicable lease terms and the current economic environment, we apply a portfolio approach for determining the incremental borrowing rate.
Other Long-Lived Assets	Other assets consist of prepaid deposits, goodwill, and other definite-lived intangible assets. Goodwill represents the excess of the purchase price over the fair value of net assets acquired. Goodwill is reviewed for impairment annually. The identifiable intangible assets are amortized on a straight-line basis over their estimated life.
Accounting Estimates	The preparation of the consolidated financial statements in conformity with U.S. generally accepted accounting principles ('GAAP') requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities, revenues and expenses, and the disclosure of contingent liabilities. Actual results could differ from those estimates.
Insurance Reserves	We are self-insured for certain losses relating to workers' compensation, automobile, health, and general liability costs. Specific stop-loss coverage is provided for catastrophic claims in order to limit exposure to significant claims. Self-insurance liabilities are based on our estimate of reported claims and claims incurred but not yet reported.
Product Warranties	We offer a basic limited warranty for certain of our products. The specific terms and conditions of those warranties vary depending upon the product sold. We typically recoup these costs through product warranties we hold with the original equipment manufacturers. Our warranty expense has historically been minimal.
Stock-Based Compensation	We estimate the value of stock option grants using a Black-Scholes valuation model. Stock-based compensation expense is recognized on a straight-line basis over the vesting period. Our stock-based compensation expense is recorded in operating and administrative expenses.
Income Taxes	We account for income taxes under the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. We recognize the effect of income tax positions only if those positions are more likely than not to be sustained. Recognized income tax positions are measured at the largest amount that is greater than 50% likely of being realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs. We record interest and penalties related to unrecognized tax benefits in income tax expense.
Earnings Per Share	Basic net earnings per share is calculated using net earnings available to common stockholders divided by the weighted average number of shares of common stock outstanding during the year. Diluted net earnings per share is similar to basic net earnings per share except that the weighted average number of shares of common stock outstanding includes the incremental shares assumed to be issued upon the exercise of stock options considered to be 'in-the-money' (i.e., when the market price of our stock is greater than the exercise price of our outstanding stock options).
Segment Reporting	We have determined that for our North American operations we meet the aggregation criteria outlined in the accounting standards as our various operations have similar (1) economic characteristics, (2) products and services, (3) customers, (4) distribution channels, and (5) regulatory environments. Considering the insignificance of our operations outside of North America, we report as a single business segment.
Recently Adopted and Recently Issued Accounting Pronouncements	Recently Adopted Accounting Pronouncements Effective January 1, 2019, we adopted the Financial Accounting Standards Board ('FASB') Accounting Standards Update ('ASU') 2016-02, Leases (Topic 842) , which requires the recognition of lease assets and lease liabilities by lessees for those leases classified as operating leases under previous guidance. The original guidance required application on a modified retrospective basis with the earliest period presented. In August 2018, the FASB issued ASU 2018-11, Targeted Improvements to ASC 842 , which included an option to not restate comparative periods in transition and elect to use the effective date of ASC 842, Leases , as the date of initial application of transition, which we elected. As a result of the adoption of ASC 842 on January 1, 2019, we recorded both operating lease ROU assets of $227.5 and lease liabilities of $228.3 . The adoption of ASC 842 had an immaterial impact on our Consolidated Statement of Earnings and Consolidated Statement of Cash Flows for the year ended December 31, 2019. In addition, we elected the package of practical expedients permitted under the transition guidance within the new standard which allowed us to carry forward the historical lease classification. Recently Issued Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13, Measurement of Credit Losses on Financial Instruments , which changes the way entities recognize impairment of most financial assets. This update is effective for periods beginning after December 15, 2019. Short-term and long-term financial assets, as defined by the standard, are impacted by immediate recognition of estimated credit losses in the financial statements, reflecting the net amount expected to be collected. We have evaluated the requirements of this standard on our financial assets and have concluded that the adoption of this ASU, beginning January 1, 2020, will have an immaterial impact on our consolidated financial statements.

Revenue (Tables)

Revenue (Tables)	12 Months Ended
Revenue (Tables)	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	Our revenues related to the following geographic areas were as follows for the periods ended December 31: Twelve-month period 2019 2018 2017 United States $ 4,568.9 4,285.5 3,842.9 Canada and Mexico 606.8 530.8 432.3 North America 5,175.7 4,816.3 4,275.2 All other foreign countries 158.0 148.8 115.3 Total revenues $ 5,333.7 4,965.1 4,390.5 The percentages of our sales by end market were as follows for the periods ended December 31: Twelve-month period 2019 2018 2017 Manufacturing 67.5 % 66.7 % 66.5 % Non-residential construction 12.9 % 13.1 % 13.0 % Other 19.6 % 20.2 % 20.5 % 100.0 % 100.0 % 100.0 % The percentages of our sales by product line were as follows for the periods ended December 31 (1) : Twelve-month Period Type Introduced 2019 2018 2017 Fasteners (2) 1967 34.2 % 34.9 % 35.6 % Tools 1993 9.9 % 10.0 % 10.1 % Cutting tools 1996 5.7 % 5.7 % 5.8 % Hydraulics & pneumatics 1996 6.8 % 6.8 % 6.8 % Material handling 1996 5.9 % 5.8 % 5.9 % Janitorial supplies 1996 7.8 % 7.6 % 7.3 % Electrical supplies 1997 4.7 % 4.7 % 4.9 % Welding supplies 1997 4.2 % 4.1 % 4.2 % Safety supplies 1999 17.9 % 17.2 % 16.3 % Other 2.9 % 3.2 % 3.1 % 100.0 % 100.0 % 100.0 % (1) In 2018, we reclassified certain product category designations and have conformed the prior period percentages to the current year presentation. (2) The fastener product line represents fasteners and miscellaneous supplies.

Long-Lived Assets (Tables)

Long-Lived Assets (Tables)	12 Months Ended
Long-Lived Assets (Tables)	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment	Property and equipment at year end consisted of the following: Depreciable Life in Years 2019 2018 Land — $ 41.8 36.3 Buildings and improvements 15 to 40 423.7 323.1 Automated distribution and warehouse equipment 5 to 30 244.5 229.1 Shelving, industrial vending, and equipment 3 to 10 1,036.2 927.6 Transportation equipment 3 to 5 88.7 77.9 Construction in progress — 132.0 152.2 1,966.9 1,746.2 Less accumulated depreciation (943.7 ) (821.4 ) Property and equipment, net $ 1,023.2 924.8
Schedule of Long-Lived Assets by Geographic Areas	Our long-lived assets related to the following geographic areas: 2019 2018 2017 United States $ 1,238.4 947.7 919.5 Canada and Mexico 72.2 43.0 42.8 North America 1,310.6 990.7 962.3 All other foreign countries 32.1 14.6 12.5 Total long-lived assets $ 1,342.7 1,005.3 974.8

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
Accrued Expenses (Tables)	Dec. 31, 2019
Payables and Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses at year end consisted of the following: 2019 2018 Employee payroll and related taxes $ 28.7 27.6 Employee bonuses and commissions 17.9 22.8 Profit sharing contribution 13.8 13.0 Insurance reserves 41.1 37.6 Indirect taxes 67.4 63.6 Customer promotions and marketing 52.2 50.9 Other 30.4 25.3 Accrued expenses $ 251.5 240.8

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
Stockholders' Equity (Tables)	Dec. 31, 2019
Stockholders' Equity Note [Abstract]
Fair Value Assumptions for Options Granted	Date of Grant Risk-free Interest Rate Expected Life of Option in Years Expected Dividend Yield Expected Stock Volatility Estimated Fair Value of Stock Option January 2, 2019 2.5 % 5.00 2.9 % 23.96 % $ 4.40 January 2, 2018 2.2 % 5.00 2.3 % 23.45 % $ 5.02 January 3, 2017 1.9 % 5.00 2.6 % 24.49 % $ 4.20 April 19, 2016 1.3 % 5.00 2.6 % 26.34 % $ 4.09 April 21, 2015 1.3 % 5.00 2.7 % 26.84 % $ 3.68 April 22, 2014 1.8 % 5.00 2.0 % 28.55 % $ 4.79 April 16, 2013 0.7 % 5.00 1.6 % 37.42 % $ 6.33 April 17, 2012 0.9 % 5.00 1.4 % 39.25 % $ 6.85 April 19, 2011 2.1 % 5.00 1.6 % 39.33 % $ 5.60
Stock Option Plan Activity and Stock Options Granted	The following tables summarize the details of options granted under our stock option plans that were still outstanding as of December 31, 2019, and the assumptions used to value those grants. All such grants were effective at the close of business on the date of grant. Options Granted Option Exercise (Strike) Price Closing Stock Price on Date of Grant December 31, 2019 Date of Grant Options Outstanding Options Exercisable January 2, 2019 1,316,924 $ 26.00 $ 25.705 1,279,842 29,010 January 2, 2018 1,087,936 $ 27.50 $ 27.270 1,019,440 42,370 January 3, 2017 1,529,578 $ 23.50 $ 23.475 1,197,606 332,132 April 19, 2016 1,690,880 $ 23.00 $ 22.870 1,220,524 447,166 April 21, 2015 1,786,440 $ 21.00 $ 20.630 833,593 444,589 April 22, 2014 1,910,000 $ 28.00 $ 25.265 599,128 357,268 April 16, 2013 410,000 $ 27.00 $ 24.625 97,472 58,722 April 17, 2012 2,470,000 $ 27.00 $ 24.505 547,112 440,310 April 19, 2011 820,000 $ 17.50 $ 15.890 12,500 12,500 Total 13,021,758 6,807,217 2,164,067 A summary of activities under our stock option plans consisted of the following: Options Outstanding Exercise Price (1) Remaining Life (2) Outstanding as of January 1, 2019 7,999,264 $ 24.765 5.61 Granted 1,316,924 $ 26.000 9.00 Exercised (2,325,073 ) $ 25.150 Cancelled/forfeited (183,898 ) $ 24.630 Outstanding as of December 31, 2019 6,807,217 $ 24.890 6.09 Exercisable as of December 31, 2019 2,164,067 $ 24.510 4.30 Options Outstanding Exercise (1) Remaining Life (2) Outstanding as of January 1, 2018 7,897,816 $ 24.140 5.89 Granted 1,087,936 $ 27.500 9.00 Exercised (620,766 ) $ 21.655 Cancelled/forfeited (365,722 ) $ 24.430 Outstanding as of December 31, 2018 7,999,264 $ 24.765 5.61 Exercisable as of December 31, 2018 3,108,756 $ 25.530 3.69 (1) Weighted average exercise price. (2) Weighted average remaining contractual life in years.
Schedule of Common Stock Outstanding Roll Forward	Shares of common stock outstanding were as follows: 2019 2018 2017 Balance at beginning of year 571,803,838 575,183,072 578,323,848 Stock options exercised 2,325,073 620,766 659,224 Purchases of common stock — (4,000,000 ) (3,800,000 ) Balance at end of year 574,128,911 571,803,838 575,183,072
Reconciliation of Denominators used in Computation of Basic and Diluted Earnings per Share	The following tables present a reconciliation of the denominators used in the computation of basic and diluted earnings per share and a summary of the options to purchase shares of common stock which were excluded from the diluted earnings calculation because they were anti-dilutive: Reconciliation 2019 2018 2017 Basic weighted average shares outstanding 573,202,152 573,933,834 576,416,870 Weighted shares assumed upon exercise of stock options 1,239,476 391,694 268,596 Diluted weighted average shares outstanding 574,441,628 574,325,528 576,685,466
Anti-Dilutive Options Excluded	Summary of Anti-dilutive Options Excluded 2019 2018 2017 Options to purchase shares of common stock — 3,159,514 7,048,802 Weighted average exercise prices of options $ — 27.510 24.925

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Earnings Before Income Taxes	Earnings before income taxes were derived from the following sources: 2019 2018 2017 Domestic $ 977.6 905.0 809.4 Foreign 66.1 82.0 63.7 Earnings before income taxes $ 1,043.7 987.0 873.1
Components of Income Tax Expense (Benefit)	Components of income tax expense (benefit) were as follows: 2019: Current Deferred Total Federal $ 177.4 11.3 188.7 State 41.6 0.2 41.8 Foreign 22.1 0.2 22.3 Income tax expense $ 241.1 11.7 252.8 2018: Current Deferred Total Federal $ 143.8 27.4 171.2 State 38.8 0.2 39.0 Foreign 24.1 0.8 24.9 Income tax expense $ 206.7 28.4 235.1 2017: Current Deferred Total Federal $ 270.6 (33.1 ) 237.5 State 33.2 3.3 36.5 Foreign 20.5 (0.0 ) 20.5 Income tax expense $ 324.3 (29.8 ) 294.5
Difference In Income Tax Expense And Expected Expense	Income tax expense in the accompanying consolidated financial statements differed from the expected expense as follows: 2019 2018 2017 U.S. federal statutory income tax rate 21.0 % 21.0 % 35.0 % U.S. federal income tax expense at statutory rate $ 219.2 207.3 305.6 Increase (decrease) attributed to: State income taxes, net of federal benefit 32.8 30.2 21.5 Transition tax — 1.2 6.5 Remeasurement of deferred taxes for Tax Act — (11.5 ) (30.8 ) Other, net 0.8 7.9 (8.3 ) Total income tax expense $ 252.8 235.1 294.5 Effective income tax rate 24.2 % 23.8 % 33.7 %
Summary of Temporary Differences That Give Rise to Deferred Income Tax Assets And Liabilities	The tax effects of temporary differences that give rise to deferred income tax assets and liabilities at year end consisted of the following: 2019 2018 Deferred income tax assets (liabilities): Inventory costing and valuation methods $ 4.3 4.2 Allowance for doubtful accounts 2.7 3.2 Insurance reserves 9.1 8.1 Customer promotions 1.9 1.9 Stock-based compensation 3.9 5.6 Operating lease liabilities 62.5 — Federal and state benefit of uncertain tax positions 0.8 0.8 Foreign net operating loss and credit carryforwards 3.2 3.2 Foreign valuation allowances (2.8 ) (2.7 ) Other, net (0.0 ) 1.3 Total deferred income tax assets 85.6 25.6 Property and equipment (114.7 ) (104.7 ) Operating lease ROU assets (61.7 ) — Total deferred income tax liabilities (176.4 ) (104.7 ) Deferred income tax liabilities $ (90.8 ) (79.1 )
Reconciliation of The Beginning and Ending Amount of Total Gross Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of total gross unrecognized tax benefits was as follows: 2019 2018 Balance at beginning of year: $ 5.3 4.4 Increase related to prior year tax positions 0.2 1.8 Decrease related to prior year tax positions (0.2 ) (0.6 ) Increase related to current year tax positions 4.7 0.7 Decrease related to statute of limitation lapses (1.4 ) (0.9 ) Settlements 0.0 (0.1 ) Balance at end of year: $ 8.6 5.3

Operating Leases (Tables)

Operating Leases (Tables)	12 Months Ended
Operating Leases (Tables)	Dec. 31, 2019
Leases [Abstract]
Cost Components of Operating Leases, Weighted Average Lease Terms, and Discount Rates	The weighted average remaining lease terms and discount rates for all of our operating leases were as follows as of December 31, 2019: Remaining lease term and discount rate: December 31, 2019 Weighted average remaining lease term (years) Leased facilities and equipment 3.26 Leased vehicles 2.89 Weighted average discount rate Lease facilities and equipment 3.18% Leased vehicles 2.70% The cost components of our operating leases were as follows for the period ended December 31, 2019: Twelve-month Period Leased Facilities and Equipment Leased Vehicles Total Operating lease cost $ 104.0 14.1 118.1 Variable lease cost 10.0 1.9 11.9 Short-term lease cost — 27.4 27.4 Total $ 114.0 43.4 157.4
Maturities of Lease Liabilities	Maturities of our lease liabilities for all operating leases are as follows as of December 31, 2019: Leased Facilities and Equipment Leased Vehicles Total 2020 $ 88.3 12.7 101.0 2021 63.2 8.5 71.7 2022 39.5 6.0 45.5 2023 22.5 2.9 25.4 2024 10.0 0.1 10.1 2025 and thereafter 3.7 — 3.7 Total lease payments $ 227.2 30.2 257.4 Less: Imputed interest (10.8 ) (1.0 ) (11.8 ) Present value of lease liabilities $ 216.4 29.2 245.6
Supplemental Cash Flow Information	Supplemental cash flow information related to our operating leases was as follows for the period ended December 31, 2019: Twelve-month Period Cash paid for amounts included in the measurement of lease liabilities: Operating cash outflow from operating leases $ 117.2 Leased assets obtained in exchange for new operating lease liabilities 116.1

Debt Commitments (Tables)

Debt Commitments (Tables)	12 Months Ended
Debt Commitments (Tables)	Dec. 31, 2019
Debt Disclosure [Abstract]
Schedule of Debt Obligations and Letters of Credit Outstanding	Debt obligations and letters of credit outstanding at year end consisted of the following: 2019 2018 Outstanding loans under unsecured revolving credit facility $ 210.0 365.0 2.00% Senior unsecured promissory note payable 40.0 40.0 2.45% Senior unsecured promissory note payable 35.0 35.0 3.22% Senior unsecured promissory note payable 60.0 60.0 Total debt 345.0 500.0 Less: Current portion of debt (3.0 ) (3.0 ) Long-term debt $ 342.0 497.0 Outstanding letters of credit under unsecured revolving credit facility - contingent obligation $ 36.3 36.3

Selected Quarterly Financial _2

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
Selected Quarterly Financial Data (Unaudited) (Tables)	Dec. 31, 2019
Selected Quarterly Financial Information [Abstract]
Schedule of Quarterly Financial Information	(Amounts in millions except per share information) 2019: Net Sales Gross Profit Pre-tax Earnings Net Earnings Basic Net (1) Diluted Net Earnings per Share (1) First quarter $ 1,309.3 624.7 257.5 194.1 0.34 0.34 Second quarter 1,368.4 641.2 271.4 204.6 0.36 0.36 Third quarter 1,379.1 651.1 278.4 213.5 0.37 0.37 Fourth quarter 1,276.9 598.4 236.4 178.7 0.31 0.31 Total $ 5,333.7 2,515.4 1,043.7 790.9 1.38 1.38 2018: Net Sales Gross Profit Pre-tax Earnings Net Earnings Basic Net (1) Diluted Net Earnings per Share (1) First quarter $ 1,185.8 577.6 231.9 174.3 0.30 0.30 Second quarter 1,267.9 617.7 265.9 211.2 0.37 0.37 Third quarter 1,279.8 615.8 259.4 197.6 0.34 0.34 Fourth quarter 1,231.6 587.8 229.8 168.8 0.29 0.29 Total $ 4,965.1 2,398.9 987.0 751.9 1.31 1.31 (1) Amounts may not foot due to rounding difference.

Business Overview and Summary_3

Business Overview and Summary of Significant Accounting Policies - Additional Information (Details)	May 22, 2019$ / sharesshares	Dec. 31, 2019USD ($)location$ / sharesshares	Dec. 31, 2018USD ($)$ / sharesshares	Dec. 31, 2017USD ($)	Jan. 01, 2019USD ($)
Accounting Policies [Abstract]
Approximate number of in-market locations \| location		3,200
Impairment of property and equipment long-lived assets		$ 0	$ 0	$ 0
Non-cancelable lease term, pick-up truck, (less than)		1 year
Two-for-one stock split	2
Par value (in dollars per share) \| $ / shares	$ 0.01	$ 0.01	$ 0.01
Issued, additional (in shares) \| shares	1	574,128,911	571,803,838
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets		$ 243,200,000	$ 0
Operating lease liabilities		$ 245,600,000
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets					$ 227,500,000
Operating lease liabilities					$ 228,300,000

Revenue - Revenues by Geographi

Revenue - Revenues by Geographic Areas (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues by Geographic Areas [Line Items]
Total revenues	$ 1,276.9	$ 1,379.1	$ 1,368.4	$ 1,309.3	$ 1,231.6	$ 1,279.8	$ 1,267.9	$ 1,185.8	$ 5,333.7	$ 4,965.1	$ 4,390.5
United States
Revenues by Geographic Areas [Line Items]
Total revenues									4,568.9	4,285.5	3,842.9
Canada and Mexico
Revenues by Geographic Areas [Line Items]
Total revenues									606.8	530.8	432.3
North America
Revenues by Geographic Areas [Line Items]
Total revenues									5,175.7	4,816.3	4,275.2
All other foreign countries
Revenues by Geographic Areas [Line Items]
Total revenues									$ 158	$ 148.8	$ 115.3

Revenue - Percentages of Sales

Revenue - Percentages of Sales by End Market (Details) - End Market - Sales	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Percentage of Sales by End Market [Line Items]
Percentage of sales	100.00%	100.00%	100.00%
Manufacturing
Percentage of Sales by End Market [Line Items]
Percentage of sales	67.50%	66.70%	66.50%
Non-residential construction
Percentage of Sales by End Market [Line Items]
Percentage of sales	12.90%	13.10%	13.00%
Other
Percentage of Sales by End Market [Line Items]
Percentage of sales	19.60%	20.20%	20.50%

Revenue - Percentages of Sale_2

Revenue - Percentages of Sales by Product Line (Details) - Product Line - Sales	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Percentage of Sales by Product Line [Line Items]
Percentage of sales	100.00%	100.00%	100.00%
Fasteners
Percentage of Sales by Product Line [Line Items]
Percentage of sales	34.20%	34.90%	35.60%
Tools
Percentage of Sales by Product Line [Line Items]
Percentage of sales	9.90%	10.00%	10.10%
Cutting tools
Percentage of Sales by Product Line [Line Items]
Percentage of sales	5.70%	5.70%	5.80%
Hydraulics and pneumatics
Percentage of Sales by Product Line [Line Items]
Percentage of sales	6.80%	6.80%	6.80%
Material handling
Percentage of Sales by Product Line [Line Items]
Percentage of sales	5.90%	5.80%	5.90%
Janitorial supplies
Percentage of Sales by Product Line [Line Items]
Percentage of sales	7.80%	7.60%	7.30%
Electrical supplies
Percentage of Sales by Product Line [Line Items]
Percentage of sales	4.70%	4.70%	4.90%
Welding supplies
Percentage of Sales by Product Line [Line Items]
Percentage of sales	4.20%	4.10%	4.20%
Safety supplies
Percentage of Sales by Product Line [Line Items]
Percentage of sales	17.90%	17.20%	16.30%
Other
Percentage of Sales by Product Line [Line Items]
Percentage of sales	2.90%	3.20%	3.10%

Long-Lived Assets - Property An

Long-Lived Assets - Property And Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Property and Equipment, Net [Line Items]
Property and equipment	$ 1,966.9	$ 1,746.2
Less accumulated depreciation	(943.7)	(821.4)
Property and equipment, net	1,023.2	924.8
Land
Property and Equipment, Net [Line Items]
Property and equipment	41.8	36.3
Buildings and improvements
Property and Equipment, Net [Line Items]
Property and equipment	423.7	323.1
Automated distribution and warehouse equipment
Property and Equipment, Net [Line Items]
Property and equipment	244.5	229.1
Shelving, industrial vending, and equipment
Property and Equipment, Net [Line Items]
Property and equipment	1,036.2	927.6
Transportation equipment
Property and Equipment, Net [Line Items]
Property and equipment	88.7	77.9
Construction in progress
Property and Equipment, Net [Line Items]
Property and equipment	$ 132	$ 152.2
Minimum \| Buildings and improvements
Property and Equipment, Net [Line Items]
Depreciable life in years	15 years
Minimum \| Automated distribution and warehouse equipment
Property and Equipment, Net [Line Items]
Depreciable life in years	5 years
Minimum \| Shelving, industrial vending, and equipment
Property and Equipment, Net [Line Items]
Depreciable life in years	3 years
Minimum \| Transportation equipment
Property and Equipment, Net [Line Items]
Depreciable life in years	3 years
Maximum \| Buildings and improvements
Property and Equipment, Net [Line Items]
Depreciable life in years	40 years
Maximum \| Automated distribution and warehouse equipment
Property and Equipment, Net [Line Items]
Depreciable life in years	30 years
Maximum \| Shelving, industrial vending, and equipment
Property and Equipment, Net [Line Items]
Depreciable life in years	10 years
Maximum \| Transportation equipment
Property and Equipment, Net [Line Items]
Depreciable life in years	5 years

Long-Lived Assets - Geographic

Long-Lived Assets - Geographic Areas (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Long-Lived Assets by Geographic Areas [Line Items]
Total long-lived Assets	$ 1,342.7	$ 1,005.3	$ 974.8
United States
Long-Lived Assets by Geographic Areas [Line Items]
Total long-lived Assets	1,238.4	947.7	919.5
Canada and Mexico
Long-Lived Assets by Geographic Areas [Line Items]
Total long-lived Assets	72.2	43	42.8
North America
Long-Lived Assets by Geographic Areas [Line Items]
Total long-lived Assets	1,310.6	990.7	962.3
All other foreign countries
Long-Lived Assets by Geographic Areas [Line Items]
Total long-lived Assets	$ 32.1	$ 14.6	$ 12.5

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Payables and Accruals [Abstract]
Employee payroll and related taxes	$ 28.7	$ 27.6
Employee bonuses and commissions	17.9	22.8
Profit sharing contribution	13.8	13
Insurance reserves	41.1	37.6
Indirect taxes	67.4	63.6
Customer promotions and marketing	52.2	50.9
Other	30.4	25.3
Accrued expenses	$ 251.5	$ 240.8

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	Jan. 16, 2020	Jan. 02, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2019
Subsequent Event [Line Items]
Cash dividends paid per share of common stock (in dollars per share)			$ 0.87	$ 0.77	$ 0.64
Options Granted (in shares)						13,021,758
Options vesting and exercisable period, maximum			8 years
Options termination period			9 years
Total intrinsic value of stock options exercised			$ 20.2	$ 4.2	$ 6.9
Total unrecognized stock-based compensation expense			$ 13.1			$ 13.1
Weighted average period over which total unrecognized stock-based compensation expense will be recognized			3 years 9 months 25 days
Total grant date fair value of stock options vested			$ 5.9	5.3	4.2
Total stock-based compensation expense			$ 5.7	$ 5.1	$ 5.2
Subsequent Event
Subsequent Event [Line Items]
Dividend declared (in dollars per share)	$ 0.25
Options Granted (in shares)		877,299
Option Exercise (Strike) Price (in dollars per share)		$ 38
Closing Stock Price on Date of Grant (in dollars per share)		$ 37.23
Non-employee Director Options Elected (in shares)		24,964
Non-employee Director Option Exercise (Strike) Price (in dollars per share)		$ 38

Stockholders' Equity (Stock Opt

Stockholders' Equity (Stock Options Granted) (Details)	104 Months Ended
Stockholders' Equity (Stock Options Granted) (Details)	Dec. 31, 2019$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted (in shares)	13,021,758
Options Outstanding (in shares)	6,807,217
Options Exercisable (in shares)	2,164,067
January 2, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted (in shares)	1,316,924
Option Exercise (Strike) Price (in dollars per share) \| $ / shares	$ 26
Closing Stock Price on Date of Grant (in dollars per share) \| $ / shares	$ 25.705
Options Outstanding (in shares)	1,279,842
Options Exercisable (in shares)	29,010
January 2, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted (in shares)	1,087,936
Option Exercise (Strike) Price (in dollars per share) \| $ / shares	$ 27.50
Closing Stock Price on Date of Grant (in dollars per share) \| $ / shares	$ 27.270
Options Outstanding (in shares)	1,019,440
Options Exercisable (in shares)	42,370
January, 3, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted (in shares)	1,529,578
Option Exercise (Strike) Price (in dollars per share) \| $ / shares	$ 23.50
Closing Stock Price on Date of Grant (in dollars per share) \| $ / shares	$ 23.475
Options Outstanding (in shares)	1,197,606
Options Exercisable (in shares)	332,132
April 19, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted (in shares)	1,690,880
Option Exercise (Strike) Price (in dollars per share) \| $ / shares	$ 23
Closing Stock Price on Date of Grant (in dollars per share) \| $ / shares	$ 22.870
Options Outstanding (in shares)	1,220,524
Options Exercisable (in shares)	447,166
April 21, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted (in shares)	1,786,440
Option Exercise (Strike) Price (in dollars per share) \| $ / shares	$ 21
Closing Stock Price on Date of Grant (in dollars per share) \| $ / shares	$ 20.630
Options Outstanding (in shares)	833,593
Options Exercisable (in shares)	444,589
April 22, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted (in shares)	1,910,000
Option Exercise (Strike) Price (in dollars per share) \| $ / shares	$ 28
Closing Stock Price on Date of Grant (in dollars per share) \| $ / shares	$ 25.265
Options Outstanding (in shares)	599,128
Options Exercisable (in shares)	357,268
April 16, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted (in shares)	410,000
Option Exercise (Strike) Price (in dollars per share) \| $ / shares	$ 27
Closing Stock Price on Date of Grant (in dollars per share) \| $ / shares	$ 24.625
Options Outstanding (in shares)	97,472
Options Exercisable (in shares)	58,722
April 17, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted (in shares)	2,470,000
Option Exercise (Strike) Price (in dollars per share) \| $ / shares	$ 27
Closing Stock Price on Date of Grant (in dollars per share) \| $ / shares	$ 24.505
Options Outstanding (in shares)	547,112
Options Exercisable (in shares)	440,310
April 19, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted (in shares)	820,000
Option Exercise (Strike) Price (in dollars per share) \| $ / shares	$ 17.50
Closing Stock Price on Date of Grant (in dollars per share) \| $ / shares	$ 15.890
Options Outstanding (in shares)	12,500
Options Exercisable (in shares)	12,500

Stockholders' Equity (Fair Valu

Stockholders' Equity (Fair Value Assumptions For Options Granted) (Details)	12 Months Ended
	Dec. 31, 2019$ / shares
January 2, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free Interest Rate	2.50%
Expected Life of Option in Years	5 years
Expected Dividend Yield	2.90%
Expected Stock Volatility	23.96%
Estimated Fair Value of Stock Option (in dollars per share)	$ 4.40
January 2, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free Interest Rate	2.20%
Expected Life of Option in Years	5 years
Expected Dividend Yield	2.30%
Expected Stock Volatility	23.45%
Estimated Fair Value of Stock Option (in dollars per share)	$ 5.02
January, 3, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free Interest Rate	1.90%
Expected Life of Option in Years	5 years
Expected Dividend Yield	2.60%
Expected Stock Volatility	24.49%
Estimated Fair Value of Stock Option (in dollars per share)	$ 4.20
April 19, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free Interest Rate	1.30%
Expected Life of Option in Years	5 years
Expected Dividend Yield	2.60%
Expected Stock Volatility	26.34%
Estimated Fair Value of Stock Option (in dollars per share)	$ 4.09
April 21, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free Interest Rate	1.30%
Expected Life of Option in Years	5 years
Expected Dividend Yield	2.70%
Expected Stock Volatility	26.84%
Estimated Fair Value of Stock Option (in dollars per share)	$ 3.68
April 22, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free Interest Rate	1.80%
Expected Life of Option in Years	5 years
Expected Dividend Yield	2.00%
Expected Stock Volatility	28.55%
Estimated Fair Value of Stock Option (in dollars per share)	$ 4.79
April 16, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free Interest Rate	0.70%
Expected Life of Option in Years	5 years
Expected Dividend Yield	1.60%
Expected Stock Volatility	37.42%
Estimated Fair Value of Stock Option (in dollars per share)	$ 6.33
April 17, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free Interest Rate	0.90%
Expected Life of Option in Years	5 years
Expected Dividend Yield	1.40%
Expected Stock Volatility	39.25%
Estimated Fair Value of Stock Option (in dollars per share)	$ 6.85
April 19, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free Interest Rate	2.10%
Expected Life of Option in Years	5 years
Expected Dividend Yield	1.60%
Expected Stock Volatility	39.33%
Estimated Fair Value of Stock Option (in dollars per share)	$ 5.60

Stockholder's Equity (Summary O

Stockholder's Equity (Summary Of Stock Option Plan Activity) (Details) - $ / shares	12 Months Ended			104 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2019
Options Outstanding
Granted (in shares)				13,021,758
Exercised (in shares)	(2,325,073)	(620,766)	(659,224)
Outstanding as of End of Period (in shares)	6,807,217			6,807,217
Exercisable (in shares)	2,164,067			2,164,067
Stock Option Plan
Options Outstanding
Outstanding as of Beginning of Period (in shares)	7,999,264	7,897,816
Granted (in shares)	1,316,924	1,087,936
Exercised (in shares)	(2,325,073)	(620,766)
Cancelled/forfeited (in shares)	(183,898)	(365,722)
Outstanding as of End of Period (in shares)	6,807,217	7,999,264	7,897,816	6,807,217
Exercisable (in shares)	2,164,067	3,108,756		2,164,067
Exercise Price
Outstanding as of Beginning of Period (in dollars per share)	$ 24.765	$ 24.140
Granted (in dollars per share)	26	27.500
Exercised (in dollars per share)	25.150	21.655
Cancelled/forfeited (in dollars per share)	24.630	24.430
Outstanding as of End of Period (in dollars per share)	24.890	24.765	$ 24.140	$ 24.890
Exercisable (in dollars per share)	$ 24.510	$ 25.530		$ 24.510
Remaining Life
Outstanding	6 years 1 month 2 days	5 years 7 months 9 days	5 years 10 months 20 days
Granted	9 years	9 years
Exercisable	4 years 3 months 18 days	3 years 8 months 8 days

Stockholders' Equity (Shares Ou

Stockholders' Equity (Shares Outstanding) (Details) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Shares Outstanding [Roll Forward]
Balance at beginning of year (in shares)	571,803,838	575,183,072	578,323,848
Stock options exercised (in shares)	2,325,073	620,766	659,224
Purchases of common stock (in shares)	0	(4,000,000)	(3,800,000)
Balance at end of year (in shares)	574,128,911	571,803,838	575,183,072

Stockholders' Equity (Reconcili

Stockholders' Equity (Reconciliation Of Denominators Used In Computation Of Basic And Diluted Earnings Per Share) (Details) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stockholders' Equity Note [Abstract]
Basic weighted average shares outstanding (in shares)	573,202,152	573,933,834	576,416,870
Weighted shares assumed upon exercise of stock options (in shares)	1,239,476	391,694	268,596
Diluted weighted average shares outstanding (in shares)	574,441,628	574,325,528	576,685,466

Stockholders' Equity (Summary O

Stockholders' Equity (Summary Of Anti-Dilutive Options Excluded) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stockholders' Equity Note [Abstract]
Options to purchase shares of common stock (in shares)	0	3,159,514	7,048,802
Weighted average exercise prices of options (in dollars per share)	$ 0	$ 27.510	$ 24.925

Retirement Savings Plan (Narrat

Retirement Savings Plan (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Contribution Plan [Abstract]
Expense related to contribution to employees' retirement accounts	$ 13.8	$ 13	$ 10.6

Income Taxes (Earnings Before I

Income Taxes (Earnings Before Income Taxes) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Domestic									$ 977.6	$ 905	$ 809.4
Foreign									66.1	82	63.7
Earnings before income taxes	$ 236.4	$ 278.4	$ 271.4	$ 257.5	$ 229.8	$ 259.4	$ 265.9	$ 231.9	$ 1,043.7	$ 987	$ 873.1

Income Taxes (Components Of Inc

Income Taxes (Components Of Income Tax Expense (Benefit)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current
Federal	$ 177.4	$ 143.8	$ 270.6
State	41.6	38.8	33.2
Foreign	22.1	24.1	20.5
Income tax expense	241.1	206.7	324.3
Deferred
Federal	11.3	27.4	(33.1)
State	0.2	0.2	3.3
Foreign	0.2	0.8	0
Income tax expense	11.7	28.4	(29.8)
Total
Federal	188.7	171.2	237.5
State	41.8	39	36.5
Foreign	22.3	24.9	20.5
Income tax expense	$ 252.8	$ 235.1	$ 294.5

Income Taxes (Difference In Inc

Income Taxes (Difference In Income Tax Expense And Expected Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
U.S. federal statutory income tax rate	21.00%	21.00%	35.00%
U.S. federal income tax expense at statutory rate	$ 219.2	$ 207.3	$ 305.6
State income taxes, net of federal benefit	32.8	30.2	21.5
Transition tax	0	1.2	6.5
Remeasurement of deferred taxes for Tax Act	0	(11.5)	(30.8)
Other, net	0.8	7.9	(8.3)
Income tax expense	$ 252.8	$ 235.1	$ 294.5
Effective income tax rate	24.20%	23.80%	33.70%

Income Taxes (Summary Of Tempor

Income Taxes (Summary Of Temporary Differences That Give Rise To Deferred Income Tax Assets And Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Deferred income tax assets (liabilities):
Inventory costing and valuation methods	$ 4.3	$ 4.2
Allowance for doubtful accounts	2.7	3.2
Insurance reserves	9.1	8.1
Customer promotions	1.9	1.9
Stock-based compensation	3.9	5.6
Operating lease liabilities	62.5	0
Federal and state benefit of uncertain tax positions	0.8	0.8
Foreign net operating loss and credit carryforwards	3.2	3.2
Foreign valuation allowances	(2.8)	(2.7)
Other, net	0	1.3
Total deferred income tax assets	85.6	25.6
Property and equipment	(114.7)	(104.7)
Operating lease ROU assets	(61.7)	0
Total deferred income tax liabilities	(176.4)	(104.7)
Deferred income tax liabilities	$ (90.8)	$ (79.1)

Income Taxes (Reconciliation Of

Income Taxes (Reconciliation Of The Beginning And Ending Amount Of Total Gross Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year:	$ 5.3	$ 4.4
Increase related to prior year tax positions	0.2	1.8
Decrease related to prior year tax positions	(0.2)	(0.6)
Increase related to current year tax positions	4.7	0.7
Decrease related to statute of limitation lapses	(1.4)	(0.9)
Settlements	0	(0.1)
Balance at end of year:	$ 8.6	$ 5.3

Income Taxes (Additional Inform

Income Taxes (Additional Information) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income tax expense	$ 252.8	$ 235.1	$ 294.5
Income tax expense, percent of earnings before income taxes	24.20%	23.80%	33.70%
Income tax benefit attributable to discrete income tax items		$ 7.1
Undistributed earnings from foreign subsidiaries	$ 288.1

Operating Leases - Additional I

Operating Leases - Additional Information (Details) $ in Millions	Dec. 31, 2019USD ($)
Leases [Abstract]
Aggregate residual value guarantee of pick-up leases	$ 90

Operating leases - Cost Compone

Operating leases - Cost Components of Operating Leases (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 118.1
Variable lease cost	11.9
Short-term lease cost	27.4
Total	157.4
Leased Facilities and Equipment
Lessee, Lease, Description [Line Items]
Operating lease cost	104
Variable lease cost	10
Short-term lease cost	0
Total	114
Leased Vehicles
Lessee, Lease, Description [Line Items]
Operating lease cost	14.1
Variable lease cost	1.9
Short-term lease cost	27.4
Total	$ 43.4

Operating Leases - Maturities o

Operating Leases - Maturities of Lease Liabilities (Details) $ in Millions	Dec. 31, 2019USD ($)
Lessee, Lease, Description [Line Items]
2020	$ 101
2021	71.7
2022	45.5
2023	25.4
2024	10.1
2025 and thereafter	3.7
Total lease payments	257.4
Less: Imputed interest	(11.8)
Present value of lease liabilities	245.6
Leased Facilities and Equipment
Lessee, Lease, Description [Line Items]
2020	88.3
2021	63.2
2022	39.5
2023	22.5
2024	10
2025 and thereafter	3.7
Total lease payments	227.2
Less: Imputed interest	(10.8)
Present value of lease liabilities	216.4
Leased Vehicles
Lessee, Lease, Description [Line Items]
2020	12.7
2021	8.5
2022	6
2023	2.9
2024	0.1
2025 and thereafter	0
Total lease payments	30.2
Less: Imputed interest	(1)
Present value of lease liabilities	$ 29.2

Operating Leases - Weighted Ave

Operating Leases - Weighted Average Lease term and Discount Rates (Details)	Dec. 31, 2019
Leased Facilities and Equipment
Lessee, Lease, Description [Line Items]
Weighted average remaining lease term (years)	3 years 3 months 3 days
Weighted average discount rate	3.18%
Leased Vehicles
Lessee, Lease, Description [Line Items]
Weighted average remaining lease term (years)	2 years 10 months 20 days
Weighted average discount rate	2.70%

Operating Leases - Supplemental

Operating Leases - Supplemental Cash Flow Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash outflow from operating leases	$ 117.2
Leased assets obtained in exchange for new operating lease liabilities	$ 116.1

Debt Commitments - Debt Obligat

Debt Commitments - Debt Obligations and Letters of Credit Outstanding (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Total debt	$ 345	$ 500
Less: Current portion of debt	(3)	(3)
Long-term debt	342	497
Credit Facility \| Unsecured Revolving Credit Facility
Debt Instrument [Line Items]
Total debt	210	365
Credit Facility \| Letter of Credit Subfacility
Debt Instrument [Line Items]
Outstanding letters of credit under unsecured revolving credit facility - contingent obligation	$ 36.3	36.3
Senior Unsecured Promissory Notes \| 2.00% Senior Unsecured Promissory Note Payable
Debt Instrument [Line Items]
Fixed interest rate per annum	2.00%
Total debt	$ 40	40
Senior Unsecured Promissory Notes \| 2.45% Senior Unsecured Promissory Note Payable
Debt Instrument [Line Items]
Fixed interest rate per annum	2.45%
Total debt	$ 35	35
Senior Unsecured Promissory Notes \| 3.22% Senior Unsecured Promissory Note Payable
Debt Instrument [Line Items]
Fixed interest rate per annum	3.22%
Total debt	$ 60	$ 60

Debt Commitments - Unsecured Re

Debt Commitments - Unsecured Revolving Credit Facility (Details) - Credit Facility	12 Months Ended
	Dec. 31, 2019USD ($)
Debt Instrument [Line Items]
Weighted per annum interest rate on outstanding line of credit	2.70%
Minimum
Debt Instrument [Line Items]
Percentage fee paid for unused portion of credit facility	0.10%
Maximum
Debt Instrument [Line Items]
Percentage fee paid for unused portion of credit facility	0.125%
LIBOR
Debt Instrument [Line Items]
Per annum interest rate over LIBOR	0.95%
Unsecured Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity	$ 700,000,000
Letter of Credit Subfacility
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity	$ 55,000,000

Debt Commitments - Senior Unsec

Debt Commitments - Senior Unsecured Promissory Notes Payable (Details) - Senior Unsecured Promissory Notes	Dec. 31, 2019USD ($)debt_instrument_series
Debt Instrument [Line Items]
Debt issuance, aggregate principal amount	$ 135,000,000
Maximum aggregate borrowing capacity	$ 600,000,000
Number of debt instrument Series \| debt_instrument_series	3
2.00% Senior Unsecured Promissory Note Payable
Debt Instrument [Line Items]
Debt issuance, aggregate principal amount	$ 40,000,000
Fixed interest rate per annum	2.00%
2.45% Senior Unsecured Promissory Note Payable
Debt Instrument [Line Items]
Debt issuance, aggregate principal amount	$ 35,000,000
Fixed interest rate per annum	2.45%
3.22% Senior Unsecured Promissory Note Payable
Debt Instrument [Line Items]
Debt issuance, aggregate principal amount	$ 60,000,000
Fixed interest rate per annum	3.22%

Selected Quarterly Financial _3

Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Selected Quarterly Financial Information [Abstract]
Net Sales	$ 1,276.9	$ 1,379.1	$ 1,368.4	$ 1,309.3	$ 1,231.6	$ 1,279.8	$ 1,267.9	$ 1,185.8	$ 5,333.7	$ 4,965.1	$ 4,390.5
Gross Profit	598.4	651.1	641.2	624.7	587.8	615.8	617.7	577.6	2,515.4	2,398.9	2,163.6
Pre-tax Earnings	236.4	278.4	271.4	257.5	229.8	259.4	265.9	231.9	1,043.7	987	873.1
Net Earnings	$ 178.7	$ 213.5	$ 204.6	$ 194.1	$ 168.8	$ 197.6	$ 211.2	$ 174.3	$ 790.9	$ 751.9	$ 578.6
Basic Net Earnings per Share (in dollars per share)	$ 0.31	$ 0.37	$ 0.36	$ 0.34	$ 0.29	$ 0.34	$ 0.37	$ 0.30	$ 1.38	$ 1.31	$ 1
Diluted Net Earnings per Share (in dollars per share)	$ 0.31	$ 0.37	$ 0.36	$ 0.34	$ 0.29	$ 0.34	$ 0.37	$ 0.30	$ 1.38	$ 1.31	$ 1

Schedule II-Valuation and Qua_2

Schedule II-Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Allowance For Doubtful Accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	$ 12.8	$ 11.9	$ 11.2
Additions Charged to Costs and Expenses	5.5	8.1	8.2
Other Additions (Deductions)	0	0	0
Less Deductions	7.4	7.2	7.5
Balance at End of Year	10.9	12.8	11.9
Insurance Reserves
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	37.6	39	34.6
Additions Charged to Costs and Expenses	69.7	66.9	68.2
Other Additions (Deductions)	0	0	0
Less Deductions	66.2	68.3	63.8
Balance at End of Year	$ 41.1	$ 37.6	$ 39