Securities. Securities available-for-sale increased $5.1 million, or 4.7%, to $114.4 million at September 30, 2023 from $109.3 million at December 31, 2022, driven by purchases of $17.9 million, partially offset by paydowns of $9.4 million and unrealized losses of $3.2 million. Securities held-to-maturity increased $402 thousand, or 0.5%, to $78.8 million at September 30, 2023 from $78.4 million at December 31, 2022, driven by purchases of $6.0 million, partially offset by paydowns of $5.5 million.
Funding. Total deposits increased $54.4 million, or 4.4%, to $1.3 billion at September 30, 2023 from $1.2 billion at December 31, 2022. We continue to focus on the acquisition and expansion of core deposit relationships. Core deposits, which we define as total deposits excluding time deposits, totaled $1.3 billion at September 30, 2023, or 99.4% of total deposits, compared to $1.2 billion or 98.4% of total deposits at December 31, 2022. Litigation and payment processing deposits represent $1.1 billion, or 85%, of total deposits at September 30, 2023. Demand deposits (noninterest bearing) increased $27.7 million, or 6.2%, to $472.1 million, representing 36.8% of total deposits at September 30, 2023.
Core commercial relationship banking clients in our two national verticals represent approximately 85% of our $1.3 billion deposit base at September 30, 2023. These relationship banking clients are derived from coupling lending facilities, payment processing, and other unique custodial banking needs with commercial cash management depository services, leading to no client attrition during the recent market turmoil through September 30, 2023. Our deposit strategy primarily focuses on developing full commercial banking relationships with our clients through lending facilities, payment processing, and other unique service orientated relationships in our two national verticals, rather than just competing with other institutions on rate. Our longer duration IOLTA, escrow and claimant trust settlement deposits represent $651.9 million, or 50.8%, of total deposits. These law firm escrow accounts, as well as other fiduciary deposit accounts, are for the benefit of the law firm’s clients (or claimants) and are titled in a manner to ensure that the maximum amount of FDIC insurance coverage passes through the account to the beneficial owner of the funds held in the account. Therefore, these law firm escrow accounts carry FDIC insurance at the claimant settlement level, not at the deposit account level. As of September 30, 2023, uninsured deposits were $373.1 million, or 29%, of our total deposits of $1.3 billion, excluding $6.7 million of affiliate deposits held by the Bank. Approximately 85% of our uninsured deposits represent clients with full relationship banking (loans, payment processing, and other service oriented relationships) including, but not limited to, law firm operating accounts, law firm escrow accounts, merchant reserves, ISO reserves, ACH processing, and custodial accounts.
Due to the nature of our larger mass tort and class action settlements related to the litigation vertical, we participate in FDIC insured sweep programs as well as treasury secured money market funds. As of September 30, 2023, off-balance sheet sweep funds totaled approximately $457.3 million, of which approximately $310.4 million, or 67.9%, was available to be swept back onto our balance sheet as reciprocal client relationship deposits. Our deposit growth and off-balance sheet funds continue to demonstrate our highly efficient branchless and technology enabled deposit platforms.
At September 30, 2023, we had the ability to borrow a total of $279.6 million from the Federal Home Loan Bank of New York. We also had an available line of credit with the Federal Reserve Bank of New York discount window of $58.2 million. No borrowing amounts were outstanding as of September 30, 2023. Historically, we have never leveraged our balance sheet to generate earnings and have always utilized core client deposits to fund our asset growth and related earnings. Additionally, the Company has access to the Federal Reserve Bank Term Funding Program but did not draw on such facility at any time in 2023.
Equity. Total stockholders’ equity increased $27.5 million to $185.6 million at September 30, 2023, from $158.2 million at December 31, 2022, primarily due to net income of $31.1 million, amortization of share based compensation of $2.4 million, partially offset by dividends declared to common stockholders of $2.9 million, other comprehensive loss of $2.3 million due to the decrease in fair value of our available-for-sale securities portfolio, a January 1, 2023 reduction of $568 thousand, net of tax, attributable to the adoption of the CECL standard, and the repurchase of 8,000 shares at a cost of $286 thousand.
Asset Quality. There were no nonperforming assets as of September 30, 2023. The allowance for credit losses was $15.3 million, or 1.38% of total loans, as of September 30, 2023, as compared to $12.2 million, or 1.29% of total loans at December 31, 2022. As of January 1, 2023, the Company adopted the CECL Standard which increased our allowance for credit losses as a percentage of loans by 2 basis points, or $283 thousand, which was reflected as an adjustment to retained earnings. The remaining increase in the allowance as a percentage of loans was general reserve driven considering loan growth and qualitative factors associated with the current uncertain economic environment. As