Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] | Note 3: Investment Securities An analysis of the amortized cost and fair value by major categories of debt securities available for sale, which are carried at fair value with net unrealized gains (losses) reported on an after-tax basis as a component of accumulated other comprehensive income, and debt securities held to maturity, which are carried at amortized cost, before allowance for credit losses of $1 thousand at March 31, 2023 December 31, 2022, At March 31, 2023 Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value (In thousands) Debt securities available for sale Agency residential mortgage-backed securities ("MBS") $ 297,547 $ 11 $ (21,480 ) $ 276,078 Securities of U.S. Government sponsored entities 306,944 32 (9,836 ) 297,140 Obligations of states and political subdivisions 83,745 88 (1,155 ) 82,678 Corporate securities 2,286,050 832 (267,642 ) 2,019,240 Collateralized loan obligations 1,571,995 522 (30,140 ) 1,542,377 Total debt securities available for sale 4,546,281 1,485 (330,253 ) 4,217,513 Debt securities held to maturity Agency residential MBS 98,006 16 (6,480 ) 91,542 Obligations of states and political subdivisions 87,761 111 (282 ) 87,590 Corporate securities 723,553 34 (27,451 ) 696,136 Total debt securities held to maturity 909,320 161 (34,213 ) 875,268 Total $ 5,455,601 $ 1,646 $ (364,466 ) $ 5,092,781 At December 31, 2022 Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value (In thousands) Debt securities available for sale Agency residential MBS $ 311,089 $ 4 $ (25,045 ) $ 286,048 Securities of U.S. Government sponsored entities 306,336 3 (15,486 ) 290,853 Obligations of states and political subdivisions 84,024 59 (2,079 ) 82,004 Corporate securities 2,406,566 1,032 (307,643 ) 2,099,955 Collateralized loan obligations 1,587,326 527 (14,970 ) 1,572,883 Total debt securities available for sale 4,695,341 1,625 (365,223 ) 4,331,743 Debt securities held to maturity Agency residential MBS 104,852 13 (7,503 ) 97,362 Obligations of states and political subdivisions 89,208 73 (538 ) 88,743 Corporate securities 721,854 - (34,448 ) 687,406 Total debt securities held to maturity 915,914 86 (42,489 ) 873,511 Total $ 5,611,255 $ 1,711 $ (407,712 ) $ 5,205,254 The amortized cost and fair value of debt securities by contractual maturity are shown in the following tables at the dates indicated: At March 31, 2023 Debt Securities Available Debt Securities Held for Sale to Maturity Amortized Fair Amortized Fair Cost Value Cost Value (In thousands) Maturity in years: 1 year or less $ 145,818 $ 145,099 $ 17,247 $ 17,240 Over 1 to 5 years 687,888 649,204 232,935 227,496 Over 5 to 10 years 2,736,621 2,486,560 561,132 538,990 Over 10 years 678,407 660,572 - - Subtotal 4,248,734 3,941,435 811,314 783,726 MBS 297,547 276,078 98,006 91,542 Total $ 4,546,281 $ 4,217,513 $ 909,320 $ 875,268 At December 31, 2022 Debt Securities Available Debt Securities Held for Sale to Maturity Amortized Fair Amortized Fair Cost Value Cost Value (In thousands) Maturity in years: 1 year or less $ 251,578 $ 250,317 $ 12,676 $ 12,659 Over 1 to 5 years 584,707 554,596 161,653 158,409 Over 5 to 10 years 2,869,559 2,570,159 636,733 605,081 Over 10 years 678,408 670,623 - - Subtotal 4,384,252 4,045,695 811,062 776,149 MBS 311,089 286,048 104,852 97,362 Total $ 4,695,341 $ 4,331,743 $ 915,914 $ 873,511 Expected maturities of mortgage-related securities can differ from contractual maturities because borrowers have the right to call or prepay obligations with or without call or prepayment penalties. In addition, such factors as prepayments and interest rates may An analysis of the gross unrealized losses of the debt securities available for sale portfolio follows: Debt Securities Available for Sale At March 31, 2023 No. of Less than 12 months No. of 12 months or longer No. of Total Investment Unrealized Investment Unrealized Investment Unrealized Positions Fair Value Losses Positions Fair Value Losses Positions Fair Value Losses ($ in thousands) Agency residential MBS 42 $ 83,747 $ (4,497 ) 73 $ 191,408 $ (16,983 ) 115 $ 275,155 $ (21,480 ) Securities of U.S. 20 285,536 (9,836 ) - - - 20 285,536 (9,836 ) Obligations of states 17 23,259 (182 ) 43 40,388 (973 ) 60 63,647 (1,155 ) Corporate securities 39 328,761 (9,934 ) 126 1,647,784 (257,708 ) 165 1,976,545 (267,642 ) Collateralized loan 56 564,458 (23,483 ) 34 313,780 (6,657 ) 90 878,238 (30,140 ) Total 174 $ 1,285,761 $ (47,932 ) 276 $ 2,193,360 $ (282,321 ) 450 $ 3,479,121 $ (330,253 ) An analysis of gross unrecognized losses of the debt securities held to maturity portfolio follows: Debt Securities Held to Maturity At March 31, 2023 No. of Less than 12 months No. of 12 months or longer No. of Total Investment Unrecognized Investment Unrecognized Investment Unrecognized Positions Fair Value Losses Positions Fair Value Losses Positions Fair Value Losses ($ in thousands) Agency residential MBS 26 $ 4,478 $ (194 ) 72 $ 85,750 $ (6,286 ) 98 $ 90,228 $ (6,480 ) Obligations of states 28 29,115 (190 ) 5 5,594 (92 ) 33 34,709 (282 ) Corporate securities 49 683,439 (27,451 ) - - - 49 683,439 (27,451 ) Total 103 $ 717,032 $ (27,835 ) 77 $ 91,344 $ (6,378 ) 180 $ 808,376 $ (34,213 ) Based upon the Company’s March 31, 2023 March 31, 2023. The Company does not not not The Company evaluates held to maturity corporate securities individually, monitoring each issuer’s financial condition, profitability, cash flows and credit rating agency conclusions. The Company has an expectation that nonpayment of the amortized cost basis continues to be zero. The fair values of debt securities could decline in the future if interest rates increase, the general economy deteriorates, inflation increases, credit ratings decline, the issuers’ financial condition deteriorates, or the liquidity for debt securities declines. As a result, significant credit losses on debt securities may As of March 31, 2023 December 31, 2022, An analysis of the gross unrealized losses of the debt securities available for sale portfolio follows: Debt Securities Available for Sale At December 31, 2022 No. of Less than 12 months No. of 12 months or longer No. of Total Investment Unrealized Investment Unrealized Investment Unrealized Positions Fair Value Losses Positions Fair Value Losses Positions Fair Value Losses ($ in thousands) Agency residential MBS 107 $ 279,139 $ (24,222 ) 9 $ 6,110 $ (823 ) 116 $ 285,249 $ (25,045 ) Securities of U.S. 22 289,067 (15,486 ) - - - 22 289,067 (15,486 ) Obligations of states 56 65,633 (1,902 ) 8 3,265 (177 ) 64 68,898 (2,079 ) Corporate securities 133 1,521,294 (170,453 ) 56 555,727 (137,190 ) 189 2,077,021 (307,643 ) Collateralized loan 58 518,074 (13,772 ) 20 192,692 (1,198 ) 78 710,766 (14,970 ) Total 376 $ 2,673,207 $ (225,835 ) 93 $ 757,794 $ (139,388 ) 469 $ 3,431,001 $ (365,223 ) An analysis of gross unrecognized losses of the debt securities held to maturity portfolio follows: Debt Securities Held to Maturity At December 31, 2022 No. of Less than 12 months No. of 12 months or longer No. of Total Investment Unrecognized Investment Unrecognized Investment Unrecognized Positions Fair Value Losses Positions Fair Value Losses Positions Fair Value Losses ($ in thousands) Agency residential MBS 97 $ 95,814 $ (7,404 ) 2 $ 682 $ (99 ) 99 $ 96,496 $ (7,503 ) Obligations of states 54 53,536 (538 ) - - - 54 53,536 (538 ) Corporate securities 49 672,406 (34,448 ) - - - 49 672,406 (34,448 ) Total 200 $ 821,756 $ (42,390 ) 2 $ 682 $ (99 ) 202 $ 822,438 $ (42,489 ) The Company evaluates debt securities on a quarterly basis including changes in security ratings issued by rating agencies, changes in the financial condition of the issuer, and, for mortgage-backed and asset-backed securities, collateral levels, delinquency and loss information with respect to the underlying collateral, changes in the levels of subordination for the Company’s particular position within the repayment structure and remaining credit enhancement as compared to expected credit losses of the security. In addition to monitoring credit rating agency evaluations, Management performs its own evaluations regarding the credit worthiness of the issuer or the securitized assets underlying asset backed securities. The following table presents the activity in the allowance for credit losses for debt securities held to maturity: For the Three Months Ended March 31, 2023 2022 (In thousands) Allowance for credit losses: Beginning balance $ 1 $ 7 Provision - - Chargeoffs - - Recoveries - - Total ending balance $ 1 $ 7 Agency mortgage-backed securities were assigned no March 31, 2023, no The following table summarizes the amortized cost of debt securities held to maturity at March 31, 2023, Credit Risk Profile by Credit Rating At March 31, 2023 AAA/AA/A BBB+ Not Rated Total (In thousands) Agency residential MBS $ 97,485 $ - $ 521 $ 98,006 Obligations of states and political subdivisions 87,376 - 385 87,761 Corporate securities 469,017 254,536 - 723,553 Total $ 653,878 $ 254,536 $ 906 $ 909,320 There were no 30 March 31, 2023. The following table provides information about the amount of interest income earned on investment securities which is fully taxable and which is exempt from federal income tax: For the Three Months Ended March 31, 2023 2022 (In thousands) Taxable $ 54,749 $ 28,733 Tax-exempt from regular federal income tax 1,193 1,605 Total interest income from investment securities $ 55,942 $ 30,338 |