Pay vs Performance Disclosure | 12 Months Ended |
Dec. 31, 2022 USD ($) $ / shares | Dec. 31, 2021 USD ($) $ / shares | Dec. 31, 2020 USD ($) $ / shares | Dec. 31, 2019 USD ($) $ / shares | Dec. 31, 2018 USD ($) $ / shares |
Pay vs Performance Disclosure [Table] | | | | | |
Pay vs Performance [Table Text Block] | The following information is intended to show the relationship between the executive compensation actually paid by our Company and our financial performance. Year Summary Compensation Table Total for PEO-1 1 ($) Summary Compensation Table Total for PEO-2 1 ($) Compensation Actually Paid to PEO-1 2 ($) Compensation Actually Paid to PEO-2 2 ($) Average Summary Compensation Table Total for Non-PEO Named Executive Officers 2,3 ($) Average Compensation Actually Paid to Non-PEO Named Executive Officers 2,3 ($) Value of Initial Fixed $100 Investment Net Income Operating EPS Total Shareholder Return ($) 4 Peer Group Total Shareholder Return ($) 4,5 2022 8,905,419 8,871,217 19,165,333 19,247,538 3,081,295 6,745,194 138 133 739,704 8.15 2021 8,353,754 8,323,666 6,084,819 6,060,050 2,906,877 2,237,094 107 121 744,959 6.86 2020 9,158,910 8,443,364 2,393,755 2,405,315 3,315,803 1,441,879 107 88 731,773 6.88 2019 8,342,279 8,337,263 23,790,020 23,757,342 3,119,663 6,932,031 118 98 760,790 6.75 2018 7,831,616 7,797,408 4,284,243 4,403,875 2,597,771 1,405,111 83 79 701,466 6.13 | | | | |
Named Executive Officers, Footnote [Text Block] | Amounts shown are reported in the Summary Compensation Table (SCT) for the Principal Executive Officers (PEOs), Gary L. Coleman (PEO-1) and Larry M. Hutchinson (PEO-2). Summary Compensation Table | | | | |
Peer Group Issuers, Footnote [Text Block] | The Company’s peer group consists of the Standard & Poor’s (S&P) Life and Health Insurance Index and is set forth in Part II, Item 5 of the Form 10-K for the fiscal year ended December 31, 2022. | | | | |
Adjustment To PEO Compensation, Footnote [Text Block] | Amounts shown represent compensation actually paid (CAP) and include adjustments for the changes in the fair values of performance share awards and option awards, as well as adjustments for the aggregate change in the actuarial present value of accumulated benefits and actuarially-determined service costs for services rendered under all defined benefit and actuarial pension plans reported in the SCT for Messrs. Coleman (PEO-1) and Hutchinson (PEO-2) and for the average of the Non-PEO Named Executive Officers (NEOs) Frank M. Svoboda, J. Matthew Darden, Steven K. Greer, and Michael C. Majors for 2021 and 2022, and Messrs. Svoboda, Darden, Greer, and W. Michael Pressley for 2018 to 2020. To calculate the CAP, the following amounts were deducted and added to the SCT Total: PEO-1 Year SCT Total Equity Award-related Additions (Deductions) to CAP Pension-related Additions (Deductions) to CAP CAP Adjustment for the Fair Value of Equity Awards as of Year-End Adjustment for the Change in the Fair Value of the Prior Years' Awards, Unvested as of Year-End Adjustment for the Change in the Fair Value of the Prior Years' Awards that Vested during the Year Adjustment for the Aggregate Change in the Present Value of the Accumulated Benefit under the Pension Plans Adjustment for the Service Cost 2022 8,905,419 3,119,560 6,499,470 692,092 — (51,208) 19,165,333 2021 8,353,754 (321,200) (1,700,782) (309,130) — 62,177 6,084,819 2020 9,158,910 (154,340) (4,084,180) (654,480) (1,939,280) 67,125 2,393,755 2019 8,342,279 3,086,150 11,905,345 1,110,430 (717,872) 63,688 23,790,020 2018 7,831,616 (1,486,450) (1,555,361) (557,127) — 51,565 4,284,243 PEO-2 Year SCT Total Equity Award-related Additions (Deductions) to CAP Pension-related Additions (Deductions) to CAP CAP Adjustment for the Fair Value of Equity Awards as of Year-End Adjustment for the Change in the Fair Value of the Prior Years' Awards, Unvested as of Year-End Adjustment for the Change in the Fair Value of the Prior Years' Awards that Vested during the Year Adjustment for the Aggregate Change in the Present Value of the Accumulated Benefit under the Pension Plans Adjustment for the Service Cost 2022 8,871,217 3,119,560 6,499,470 692,092 — 65,199 19,247,538 2021 8,323,666 (321,200) (1,700,782) (309,130) — 67,496 6,060,050 2020 8,443,364 (154,340) (4,084,180) (654,480) (1,210,731) 65,682 2,405,315 2019 8,337,263 3,086,150 11,905,345 1,110,430 (745,486) 63,640 23,757,342 2018 7,797,408 (1,486,450) (1,527,561) (544,602) — 165,080 4,403,875 | | | | |
Non-PEO NEO Average Total Compensation Amount | $ 3,081,295 | $ 2,906,877 | $ 3,315,803 | $ 3,119,663 | $ 2,597,771 |
Non-PEO NEO Average Compensation Actually Paid Amount | $ 6,745,194 | 2,237,094 | 1,441,879 | 6,932,031 | 1,405,111 |
Adjustment to Non-PEO NEO Compensation Footnote [Text Block] | Amounts shown represent compensation actually paid (CAP) and include adjustments for the changes in the fair values of performance share awards and option awards, as well as adjustments for the aggregate change in the actuarial present value of accumulated benefits and actuarially-determined service costs for services rendered under all defined benefit and actuarial pension plans reported in the SCT for Messrs. Coleman (PEO-1) and Hutchinson (PEO-2) and for the average of the Non-PEO Named Executive Officers (NEOs) Frank M. Svoboda, J. Matthew Darden, Steven K. Greer, and Michael C. Majors for 2021 and 2022, and Messrs. Svoboda, Darden, Greer, and W. Michael Pressley for 2018 to 2020. To calculate the CAP, the following amounts were deducted and added to the SCT Total: Average Non-PEO NEOs Year SCT Total Equity Award-related Additions (Deductions) to CAP Pension-related Additions (Deductions) to CAP CAP Adjustment for the Fair Value of Equity Awards as of Year-End Adjustment for the Change in the Fair Value of the Prior Years' Awards, Unvested as of Year-End Adjustment for the Change in the Fair Value of the Prior Years' Awards that Vested during the Year Adjustment for the Aggregate Change in the Present Value of the Accumulated Benefit under the Pension Plans Adjustment for the Service Cost 2022 3,081,295 1,102,060 2,083,150 242,997 — 235,692 6,745,194 2021 2,906,877 (98,330) (420,168) (103,374) (289,742) 241,831 2,237,094 2020 3,315,803 (45,053) (1,106,602) (192,601) (737,316) 207,648 1,441,879 2019 3,119,663 949,864 2,946,444 448,501 (693,092) 160,651 6,932,031 2018 2,597,771 (474,106) (518,727) (216,747) (131,262) 148,182 1,405,111 | | | | |
Compensation Actually Paid vs. Total Shareholder Return [Text Block] | | | | | |
Compensation Actually Paid vs. Net Income [Text Block] | | | | | |
Compensation Actually Paid vs. Company Selected Measure [Text Block] | | | | | |
Tabular List [Table Text Block] | Net Operating Income EPS Underwriting Income Net Operating Income ROE | | | | |
Total Shareholder Return Amount | $ 138 | 107 | 107 | 118 | 83 |
Peer Group Total Shareholder Return Amount | 133 | 121 | 88 | 98 | 79 |
Net Income (Loss) | $ 739,704 | $ 744,959 | $ 731,773 | $ 760,790 | $ 701,466 |
Company Selected Measure Amount | $ / shares | 8.15 | 6.86 | 6.88 | 6.75 | 6.13 |
Additional 402(v) Disclosure [Text Block] | Calculated based on $100 invested as of market close on December 31, 2017, including reinvestment of dividends, for each fiscal year. | | | | |
Measure [Axis]: 1 | | | | | |
Pay vs Performance Disclosure [Table] | | | | | |
Measure Name | Net Operating Income EPS | | | | |
Measure [Axis]: 2 | | | | | |
Pay vs Performance Disclosure [Table] | | | | | |
Measure Name | Underwriting Income | | | | |
Measure [Axis]: 3 | | | | | |
Pay vs Performance Disclosure [Table] | | | | | |
Measure Name | Net Operating Income ROE | | | | |
Coleman [Member] | | | | | |
Pay vs Performance Disclosure [Table] | | | | | |
PEO Total Compensation Amount | $ 8,905,419 | $ 8,353,754 | $ 9,158,910 | $ 8,342,279 | $ 7,831,616 |
PEO Actually Paid Compensation Amount | $ 19,165,333 | 6,084,819 | 2,393,755 | 23,790,020 | 4,284,243 |
PEO Name | Gary L. Coleman | | | | |
Hutchinson [Member] | | | | | |
Pay vs Performance Disclosure [Table] | | | | | |
PEO Total Compensation Amount | $ 8,871,217 | 8,323,666 | 8,443,364 | 8,337,263 | 7,797,408 |
PEO Actually Paid Compensation Amount | $ 19,247,538 | 6,060,050 | 2,405,315 | 23,757,342 | 4,403,875 |
PEO Name | Larry M. Hutchinson | | | | |
PEO [Member] | Coleman [Member] | Equity Awards as of Year End [Member] | | | | | |
Pay vs Performance Disclosure [Table] | | | | | |
Adjustment to Compensation Amount | $ 3,119,560 | (321,200) | (154,340) | 3,086,150 | (1,486,450) |
PEO [Member] | Coleman [Member] | Adjustment, Equity Awards Granted in Prior Years, Unvested [Member] | | | | | |
Pay vs Performance Disclosure [Table] | | | | | |
Adjustment to Compensation Amount | 6,499,470 | (1,700,782) | (4,084,180) | 11,905,345 | (1,555,361) |
PEO [Member] | Coleman [Member] | Equity Awards Granted in Prior Years, Vested [Member] | | | | | |
Pay vs Performance Disclosure [Table] | | | | | |
Adjustment to Compensation Amount | 692,092 | (309,130) | (654,480) | 1,110,430 | (557,127) |
PEO [Member] | Coleman [Member] | Adjustment, Present Value of the Accumulated Benefit under the Pension Plans [Member] | | | | | |
Pay vs Performance Disclosure [Table] | | | | | |
Adjustment to Compensation Amount | 0 | 0 | (1,939,280) | (717,872) | 0 |
PEO [Member] | Coleman [Member] | Adjustment, Service Cost [Member] | | | | | |
Pay vs Performance Disclosure [Table] | | | | | |
Adjustment to Compensation Amount | (51,208) | 62,177 | 67,125 | 63,688 | 51,565 |
PEO [Member] | Hutchinson [Member] | Equity Awards as of Year End [Member] | | | | | |
Pay vs Performance Disclosure [Table] | | | | | |
Adjustment to Compensation Amount | 3,119,560 | (321,200) | (154,340) | 3,086,150 | (1,486,450) |
PEO [Member] | Hutchinson [Member] | Adjustment, Equity Awards Granted in Prior Years, Unvested [Member] | | | | | |
Pay vs Performance Disclosure [Table] | | | | | |
Adjustment to Compensation Amount | 6,499,470 | (1,700,782) | (4,084,180) | 11,905,345 | (1,527,561) |
PEO [Member] | Hutchinson [Member] | Equity Awards Granted in Prior Years, Vested [Member] | | | | | |
Pay vs Performance Disclosure [Table] | | | | | |
Adjustment to Compensation Amount | 692,092 | (309,130) | (654,480) | 1,110,430 | (544,602) |
PEO [Member] | Hutchinson [Member] | Adjustment, Present Value of the Accumulated Benefit under the Pension Plans [Member] | | | | | |
Pay vs Performance Disclosure [Table] | | | | | |
Adjustment to Compensation Amount | 0 | 0 | (1,210,731) | (745,486) | 0 |
PEO [Member] | Hutchinson [Member] | Adjustment, Service Cost [Member] | | | | | |
Pay vs Performance Disclosure [Table] | | | | | |
Adjustment to Compensation Amount | 65,199 | 67,496 | 65,682 | 63,640 | 165,080 |
Non-PEO NEO [Member] | Equity Awards as of Year End [Member] | | | | | |
Pay vs Performance Disclosure [Table] | | | | | |
Adjustment to Compensation Amount | 1,102,060 | (98,330) | (45,053) | 949,864 | (474,106) |
Non-PEO NEO [Member] | Adjustment, Equity Awards Granted in Prior Years, Unvested [Member] | | | | | |
Pay vs Performance Disclosure [Table] | | | | | |
Adjustment to Compensation Amount | 2,083,150 | (420,168) | (1,106,602) | 2,946,444 | (518,727) |
Non-PEO NEO [Member] | Equity Awards Granted in Prior Years, Vested [Member] | | | | | |
Pay vs Performance Disclosure [Table] | | | | | |
Adjustment to Compensation Amount | 242,997 | (103,374) | (192,601) | 448,501 | (216,747) |
Non-PEO NEO [Member] | Adjustment, Present Value of the Accumulated Benefit under the Pension Plans [Member] | | | | | |
Pay vs Performance Disclosure [Table] | | | | | |
Adjustment to Compensation Amount | 0 | (289,742) | (737,316) | (693,092) | (131,262) |
Non-PEO NEO [Member] | Adjustment, Service Cost [Member] | | | | | |
Pay vs Performance Disclosure [Table] | | | | | |
Adjustment to Compensation Amount | $ 235,692 | $ 241,831 | $ 207,648 | $ 160,651 | $ 148,182 |