Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] |
Note 2: Investment Securities An analysis of the amortized cost, gross unrealized gains and losses accumulated in other comprehensive income, and fair value of the available for sale investment securities portfolio follows: | | Investment Securities Available for Sale At December 31, 2017 | | | Amortized Cost | | Gross Unrealized Gains | | Gross Unrealized Losses | | Fair Value | | | (In thousands) | Securities of U.S. Government sponsored entities | | $ | 122,285 | | | $ | 1 | | | $ | (2,967 | ) | | $ | 119,319 | | Agency residential mortgage-backed securities (MBS) | | | 787,679 | | | | 522 | | | | (20,495 | ) | | | 767,706 | | Non-agency residential MBS | | | 153 | | | | 1 | | | | - | | | | 154 | | Agency commercial MBS | | | 2,244 | | | | - | | | | (25 | ) | | | 2,219 | | Securities of U.S. Government entities | | | 1,612 | | | | - | | | | (22 | ) | | | 1,590 | | Obligations of states and political subdivisions | | | 182,907 | | | | 3,796 | | | | (1,482 | ) | | | 185,221 | | Corporate securities | | | 1,123,671 | | | | 1,104 | | | | (9,277 | ) | | | 1,115,498 | | Other securities | | | 2,000 | | | | - | | | | (200 | ) | | | 1,800 | | Total | | $ | 2,222,551 | | | $ | 5,424 | | | $ | (34,468 | ) | | $ | 2,193,507 | | An analysis of the amortized cost, gross unrecognized gains and losses, and fair value of the held to maturity investment securities portfolio follows: | | Investment Securities Held to Maturity At December 31, 2017 | | | Amortized Cost | | Gross Unrecognized Gains | | Gross Unrecognized Losses | | Fair Value | | | (In thousands) | Agency residential MBS | | $ | 545,883 | | | $ | 606 | | | $ | (9,850 | ) | | $ | 536,639 | | Non-agency residential MBS | | | 4,462 | | | | 70 | | | | - | | | | 4,532 | | Agency commercial MBS | | | 9,041 | | | | - | | | | (66 | ) | | | 8,975 | | Obligations of states and political subdivisions | | | 599,478 | | | | 7,736 | | | | (2,018 | ) | | | 605,196 | | Total | | $ | 1,158,864 | | | $ | 8,412 | | | $ | (11,934 | ) | | $ | 1,155,342 | | An analysis of the amortized cost, gross unrealized gains and losses accumulated in other comprehensive income, and fair value of the available for sale investment securities portfolio follows: | | Investment Securities Available for Sale At December 31, 2016 | | | Amortized Cost | | Gross Unrealized Gains | | Gross Unrealized Losses | | Value | | | (In thousands) | Securities of U.S. Government sponsored entities | | $ | | | | $ | | | | $ | | ) | | $ | | | Agency residential MBS | | | | | | | | | | | | ) | | | | | Non-agency residential MBS | | | | | | | | | | | | ) | | | | | Securities of U.S. Government entities | | | | | | | | | | | | ) | | | | | Obligations of states and political subdivisions | | | | | | | | | | | | ) | | | | | Asset-backed securities | | | | | | | | | | | | ) | | | | | | | | | | | | | | | | | | | | | | Corporate securities | | | | | | | | | | | | ) | | | | | Other securities | | | | | | | | | | | | ) | | | | | Total | | $ | 1,908,079 | | | $ | 18,494 | | | $ | (35,815 | ) | | $ | 1,890,758 | | Federal Home Loan Mortgage Corporation Federal National Mortgage Association An analysis of the amortized cost, gross unrecognized gains and losses, and fair value of the held to maturity investment securities portfolio follows: | | Investment Securities Held to Maturity At December 31, 2016 | | | Amortized Cost | | Gross Unrecognized Gains | | Gross Unrecognized Losses | | Fair Value | | | (In thousands) | Securities of U.S. Government sponsored entities | | $ | | | | $ | | | | $ | | | | $ | | | Agency residential MBS | | | | | | | | | | | | ) | | | | | Non-agency residential MBS | | | | | | | | | | | | | | | | | Agency commercial MBS | | | | | | | | | | | | ) | | | | | Obligations of states and political subdivisions | | | | | | | | | | | | ) | | | | | Total | | $ | 1,346,312 | | | $ | 7,241 | | | $ | (12,812 | ) | | $ | 1,340,741 | | During the quarter ending December 31, 2017, the Company sold its shares of FHLMC and FNMA stock. Total proceeds from the sale were $8,704 thousand and the realized gain recorded in income was $7,955 thousand. The amortized cost and fair value of investment securities by contractual maturity are shown in the following tables at the dates indicated: | | At December 31, 2017 | | | Securities Available for Sale | | Securities Held to Maturity | | | Amortized Cost | | Fair Value | | Amortized Cost | | Fair Value | | | (In thousands) | Maturity in years: | | | | | | | | | | | | | | | | | 1 year or less | | $ | 193,337 | | | $ | 193,385 | | | $ | 50,295 | | | $ | 51,105 | | Over 1 to 5 years | | | 1,031,807 | | | | 1,023,047 | | | | 269,050 | | | | 269,471 | | Over 5 to 10 years | | | 159,266 | | | | 160,042 | | | | 277,170 | | | | 281,546 | | Over 10 years | | | 46,065 | | | | 45,154 | | | | 2,963 | | | | 3,074 | | Subtotal | | | 1,430,475 | | | | 1,421,628 | | | | 599,478 | | | | 605,196 | | MBS | | | 790,076 | | | | 770,079 | | | | 559,386 | | | | 550,146 | | Other securities | | | 2,000 | | | | 1,800 | | | | - | | | | - | | Total | | $ | 2,222,551 | | | $ | 2,193,507 | | | $ | 1,158,864 | | | $ | 1,155,342 | | | | At December 31, 2016 | | | Securities Available for Sale | | Securities Held to Maturity | | | Amortized Cost | | Fair Value | | Amortized Cost | | Fair Value | | | (In thousands) | Maturity in years: | | | | | | | | | 1 year or less | | $ | 154,693 | | | $ | 154,835 | | | $ | 14,961 | | | $ | 15,639 | | Over 1 to 5 years | | | 750,834 | | | | 745,219 | | | | 292,024 | | | | 292,062 | | Over 5 to 10 years | | | 238,077 | | | | 239,153 | | | | 318,580 | | | | 319,587 | | Over 10 years | | | 47,756 | | | | 44,416 | | | | 37,810 | | | | 38,052 | | Subtotal | | | 1,191,360 | | | | 1,183,623 | | | | 663,375 | | | | 665,340 | | MBS | | | 713,936 | | | | 693,795 | | | | 682,937 | | | | 675,401 | | Other securities | | | 2,783 | | | | 13,340 | | | | - | | | | - | | Total | | $ | 1,908,079 | | | $ | 1,890,758 | | | $ | 1,346,312 | | | $ | 1,340,741 | | 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 affect the yield on the carrying value of mortgage-related securities. At December 31, 2017 and December 31, 2016, the Company had high-risk collateralized mortgage obligations as defined by regulatory guidelines. An analysis of the gross unrealized losses of the available for sale investment securities portfolio follows: | | Investment Securities Available for Sale | | | At December 31, 2017 | | | No. of | | Less than 12 months | | No. of | | 12 months or longer | | No. of | | Total | | | Investment Positions | | Fair Value | | Unrealized Losses | | Investment Positions | | Fair Value | | Unrealized Losses | | Investment Positions | | Fair Value | | Unrealized Losses | | | ($ in thousands) | Securities of U.S. Government sponsored entities | | | | | | $ | | | | $ | ( 2 | ) | | | | | | $ | | | | $ | | ) | | | | | | $ | | | | $ | ( 2,967 | ) | Agency residential MBS | | | | | | | | | | | | ) | | | | | | | | | | | | ) | | | | | | | | | | | | ) | Non-agency residential MBS | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Agency commercial MBS | | | | | | | | | | | | ) | | | | | | | | | | | | | | | | | | | | | | | | ) | Securities of U.S. Government entities | | | | | | | | | | | | | | | | | | | | | | | | ) | | | | | | | | | | | | ) | Obligations of states and political subdivisions | | | | | | | | | | | | ) | | | | | | | | | | | | ) | | | | | | | | | | | | ) | Corporate securities | | | | | | | | | | | | ) | | | | | | | | | | | | ) | | | | | | | | | | | | ) | Other securities | | | | | | | | | | | | | | | | | | | | | | | | ) | | | | | | | | | | | | ) | Total | | | | | | $ | | | | $ | | ) | | | | | | $ | | | | $ | | ) | | | | | | $ | | | | $ | | ) | An analysis of gross unrecognized losses of the held to maturity investment securities portfolio follows: | | Investment Securities Held to Maturity | | | At December 31, 2017 | | | No. of | | Less than 12 months | | No. of | | 12 months or longer | | No. of | | Total | | | Investment Positions | | Fair Value | | Unrecognized Losses | | Investment Positions | | Fair Value | | Unrecognized Losses | | Investment Positions | | Fair Value | | Unrecognized Losses | | | ($ in thousands) | Agency residential MBS | | | 15 | | | $ | 30,218 | | | $ | (201 | ) | | | 65 | | | $ | 479,775 | | | $ | (9,649 | ) | | | 80 | | | $ | 509,993 | | | $ | (9,850 | ) | Agency commercial MBS | | | 1 | | | | 1,913 | | | | (4 | ) | | | 1 | | | | 7,062 | | | | (62 | ) | | | 2 | | | | 8,975 | | | | (66 | ) | Obligations of states and political subdivisions | | | 146 | | | | 131,032 | | | | (553 | ) | | | 59 | | | | 58,979 | | | | (1,465 | ) | | | 205 | | | | 190,011 | | | | (2,018 | ) | Total | | | 162 | | | $ | 163,163 | | | $ | (758 | ) | | | 125 | | | $ | 545,816 | | | $ | (11,176 | ) | | | 287 | | | $ | 708,979 | | | $ | (11,934 | ) | The unrealized losses on the Company’s investment securities were caused by market conditions for these types of investments, particularly changes in risk-free interest rates. The Company evaluates 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, 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. Substantially all of these securities continue to be investment grade rated by a major rating agency. 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 Company does not intend to sell any investments and has concluded that it is more likely than not that it will not be required to sell the investments prior to recovery of the amortized cost basis. Therefore, the Company does not consider these investments to be other-than-temporarily impaired as of December 31, 2017. The fair values of the investment securities could decline in the future if the general economy deteriorates, inflation increases, credit ratings decline, the issuer’s financial condition deteriorates, or the liquidity for securities declines. As a result, other than temporary impairments may occur in the future. As of December 31, 2017, $715,774 thousand of investment securities were pledged to secure public deposits and short-term borrowed funds. As of December 31, 2016, $768,845 thousand of investment securities were pledged to secure public deposits and short-term borrowed funds. An analysis of gross unrealized losses of investment securities available for sale follows: | | Investment Securities Available for Sale | | | At December 31, 2016 | | | No. of | | Less than 12 months | | No. of | | 12 months or longer | | No. of | | Total | | | Investment | | Fair | | Unrealized | | Investment | | Fair | | Unrealized | | Investment | | Fair | | Unrealized | | | Positions | | Value | | Losses | | Positions | | Value | | Losses | | Positions | | Value | | Losses | | | ($ in thousands) | Securities of U.S. Government sponsored entities | | | 8 | | | $ | 117,227 | | | $ | (2,974 | ) | | | - | | | $ | - | | | $ | - | | | | 8 | | | $ | 117,227 | | | $ | (2,974 | ) | Agency residential MBS | | | 21 | | | | 524,269 | | | | (16,494 | ) | | | 28 | | | | 122,901 | | | | (4,551 | ) | | | 49 | | | | 647,170 | | | | (21,045 | ) | Non-agency residential MBS | | | 2 | | | | 246 | | | | (1 | ) | | | - | | | | - | | | | - | | | | 2 | | | | 246 | | | | (1 | ) | Securities of U.S. Government entities | | | 2 | | | | 1,253 | | | | (9 | ) | | | 1 | | | | 772 | | | | (7 | ) | | | 3 | | | | 2,025 | | | | (16 | ) | Obligations of states and political subdivisions | | | 43 | | | | 57,989 | | | | (3,905 | ) | | | 3 | | | | 1,117 | | | | (21 | ) | | | 46 | | | | 59,106 | | | | (3,926 | ) | Asset-backed securities | | | - | | | | - | | | | - | | | | 1 | | | | 695 | | | | (1 | ) | | | 1 | | | | 695 | | | | (1 | ) | Corporate securities | | | 53 | | | | 385,175 | | | | (6,551 | ) | | | 27 | | | | 96,145 | | | | (1,117 | ) | | | 80 | | | | 481,320 | | | | (7,668 | ) | Other securities | | | - | | | | - | | | | - | | | | 1 | | | | 1,816 | | | | (184 | ) | | | 1 | | | | 1,816 | | | | (184 | ) | Total | | | 129 | | | $ | 1,086,159 | | | $ | (29,934 | ) | | | 61 | | | $ | 223,446 | | | $ | (5,881 | ) | | | 190 | | | $ | 1,309,605 | | | $ | (35,815 | ) | An analysis of gross unrecognized losses of investment securities held to maturity follows: | | Investment Securities Held to Maturity | | | At December 31, 2016 | | | No. of | | Less than 12 months | | No. of | | 12 months or longer | | No. of | | Total | | | Investment | | Fair | | Unrecognized | | Investment | | Fair | | Unrecognized | | Investment | | Fair | | Unrecognized | | | Positions | | Value | | Losses | | Positions | | Value | | Losses | | Positions | | Value | | Losses | | | ($ in thousands) | Agency residential MBS | | | 66 | | | $ | 569,876 | | | $ | (8,285 | ) | | | 3 | | | $ | 10,480 | | | $ | (317 | ) | | | 69 | | | $ | 580,356 | | | $ | (8,602 | ) | Agency commercial MBS | | | - | | | | - | | | | - | | | | 1 | | | | 7,214 | | | | (143 | ) | | | 1 | | | | 7,214 | | | | (143 | ) | Obligations of states and political subdivisions | | | 295 | | | | 272,496 | | | | (3,710 | ) | | | 12 | | | | 13,126 | | | | (357 | ) | | | 307 | | | | 285,622 | | | | (4,067 | ) | Total | | | 361 | | | $ | 842,372 | | | $ | (11,995 | ) | | | 16 | | | $ | 30,820 | | | $ | (817 | ) | | | 377 | | | $ | 873,192 | | | $ | (12,812 | ) | The following table provides information about the amount of interest income earned on investment securities which is fully taxable and which is exempt from regular federal income tax: | | For the Years Ended December 31, | | | 2017 | | 2016 | | 2015 | | | (In thousands) | | | | | | | | Taxable | | $ | 51,445 | | | $ | 42,718 | | | $ | 34,472 | | Tax-exempt from regular federal income tax | | | 20,651 | | | | 22,194 | | | | 23,616 | | Total interest income from investment securities | | $ | 72,096 | | | $ | 64,912 | | | $ | 58,088 | |
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