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Securities (Tables) | 3 Months Ended
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Mar. 31, 2018
Investments, Debt and Equity Securities [Abstract] |
Composition of Securities | The following table presents the fair values of our securities portfolio at the dates presented:
(dollars in thousands) | March 31, 2018 |  | December 31, 2017
Debt securities available for sale | 682,454 |  |  | 693,147 |
Marketable equity securities | 5,196 |  |  | 5,144 |
Total Securities | 687,650 |  |  | 698,291 |
Debt Securities Available for Sale The following tables present the amortized cost and fair value of debt securities available for sale as of March 31, 2018 and debt and equity securities available for sale as of December 31, 2017:
| March 31, 2018 |  | December 31, 2017
(dollars in thousands) | Amortized Cost |  |  | Gross Unrealized Gains |  |  | Gross Unrealized Losses |  |  | Fair Value |  |  | Amortized Cost |  |  | Gross Unrealized Gains |  |  | Gross Unrealized Losses |  |  | Fair Value |
U.S. Treasury securities | $ | 14,951 |  |  | $ | — |  |  | $ | (290 | ) |  | $ | 14,661 |  |  | $ | 19,943 |  |  | $ | — |  |  | $ | (154 | ) |  | $ | 19,789 |
Obligations of U.S. government corporations and agencies | 161,844 |  |  | 62 |  |  | (1,317 | ) |  | 160,589 |  |  | 162,045 |  |  | 341 |  |  | (193 | ) |  | 162,193 |
Collateralized mortgage obligations of U.S. government corporations and agencies | 105,063 |  |  | 2 |  |  | (2,483 | ) |  | 102,582 |  |  | 109,916 |  |  | 93 |  |  | (1,321 | ) |  | 108,688 |
Residential mortgage-backed securities of U.S. government corporations and agencies | 30,700 |  |  | 443 |  |  | (460 | ) |  | 30,683 |  |  | 32,388 |  |  | 679 |  |  | (213 | ) |  | 32,854 |
Commercial mortgage-backed securities of U.S. government corporations and agencies (1) | 255,043 |  |  | — |  |  | (6,245 | ) |  | 248,798 |  |  | 244,018 |  |  | 247 |  |  | (2,044 | ) |  | 242,221 |
Obligations of states and political subdivisions | 122,650 |  |  | 2,563 |  |  | (72 | ) |  | 125,141 |  |  | 123,159 |  |  | 4,285 |  |  | (42 | ) |  | 127,402 |
Total Debt Securities Available-for-Sale | 690,251 |  |  | 3,070 |  |  | (10,867 | ) |  | 682,454 |  |  | 691,469 |  |  | 5,645 |  |  | (3,967 | ) |  | 693,147 |
Total equity securities (2) | — |  |  | — |  |  | — |  |  | — |  |  | 3,815 |  |  | 1,330 |  |  | (1 | ) |  | 5,144 |
Total Securities | $ | 690,251 |  |  | $ | 3,070 |  |  | $ | (10,867 | ) |  | $ | 682,454 |  |  | $ | 695,284 |  |  | $ | 6,975 |  |  | $ | (3,968 | ) |  | $ | 698,291 |
(1) Includes a $5.9 million security purchase that was pending settlement as of December 31, 2017. (2) ASU 2016-01 was adopted January 1, 2018, resulting in separate classification of our marketable equity securities previously included in available-for-sale securities.
Schedule of Temporally Impaired Debt Securities | The following tables present the fair value and the age of gross unrealized losses on debt securities available for sale by investment category as of the dates presented:
| March 31, 2018
| Less Than 12 Months |  | 12 Months or More |  | Total
(dollars in thousands) | Number of Securities |  | Fair Value |  |  | Unrealized Losses |  |  | Number of Securities |  | Fair Value |  |  | Unrealized Losses |  |  | Number of Securities |  | Fair Value |  |  | Unrealized Losses |
U.S. Treasury securities | 2 |  | $ | 14,661 |  |  | $ | (290 | ) |  | — |  | $ | — |  |  | $ | — |  |  | 2 |  | $ | 14,661 |  |  | $ | (290 | )
Obligations of U.S. government corporations and agencies | 16 |  | 130,823 |  |  | (1,274 | ) |  | 1 |  | 10,000 |  |  | (43 | ) |  | 17 |  | 140,823 |  |  | (1,317 | )
Collateralized mortgage obligations of U.S. government corporations and agencies | 8 |  | 55,695 |  |  | (800 | ) |  | 7 |  | 43,184 |  |  | (1,683 | ) |  | 15 |  | 98,879 |  |  | (2,483 | )
Residential mortgage-backed securities of U.S. government corporations and agencies | 3 |  | 4,861 |  |  | (106 | ) |  | 2 |  | 7,976 |  |  | (354 | ) |  | 5 |  | 12,837 |  |  | (460 | )
Commercial mortgage-backed securities of U.S. government corporations and agencies | 22 |  | 201,051 |  |  | (4,170 | ) |  | 5 |  | 47,747 |  |  | (2,075 | ) |  | 27 |  | 248,798 |  |  | (6,245 | )
Obligations of states and political subdivisions | 5 |  | 23,700 |  |  | (72 | ) |  | — |  | — |  |  | — |  |  | 5 |  | 23,700 |  |  | (72 | )
Total Temporarily Impaired Debt Securities | 56 |  | $ | 430,791 |  |  | $ | (6,712 | ) |  | 15 |  | $ | 108,907 |  |  | $ | (4,155 | ) |  | 71 |  | $ | 539,698 |  |  | $ | (10,867 | )
| December 31, 2017
| Less Than 12 Months |  | 12 Months or More |  | Total
(dollars in thousands) | Number of Securities |  | Fair Value |  |  | Unrealized Losses |  |  | Number of Securities |  | Fair Value |  |  | Unrealized Losses |  |  | Number of Securities |  | Fair Value |  |  | Unrealized Losses |
U.S. Treasury securities | 3 |  | $ | 19,789 |  |  | $ | (154 | ) |  | — |  | $ | — |  |  | $ | — |  |  | 3 |  | $ | 19,789 |  |  | $ | (154 | )
Obligations of U.S. government corporations and agencies | 9 |  | 63,635 |  |  | (144 | ) |  | 1 |  | 10,017 |  |  | (49 | ) |  | 10 |  | 73,652 |  |  | (193 | )
Collateralized mortgage obligations of U.S. government corporations and agencies | 7 |  | 47,465 |  |  | (248 | ) |  | 7 |  | 45,809 |  |  | (1,073 | ) |  | 14 |  | 93,274 |  |  | (1,321 | )
Residential mortgage-backed securities of U.S. government corporations and agencies | 1 |  | 2,333 |  |  | (10 | ) |  | 2 |  | 8,638 |  |  | (203 | ) |  | 3 |  | 10,971 |  |  | (213 | )
Commercial mortgage-backed securities of U.S. government corporations and agencies | 14 |  | 128,300 |  |  | (775 | ) |  | 5 |  | 48,746 |  |  | (1,269 | ) |  | 19 |  | 177,046 |  |  | (2,044 | )
Obligations of states and political subdivisions | 2 |  | 10,330 |  |  | (42 | ) |  | — |  | — |  |  | — |  |  | 2 |  | 10,330 |  |  | (42 | )
Total Temporarily Impaired Debt Securities | 36 |  | $ | 271,852 |  |  | $ | (1,373 | ) |  | 15 |  | $ | 113,210 |  |  | $ | (2,594 | ) |  | 51 |  | $ | 385,062 |  |  | $ | (3,967 | )
Unrealized Gains and Losses, Net of Tax, of Debt Securities Available for Sale | The following table presents net unrealized gains and losses, net of tax, on debt securities available-for-sale included in accumulated other comprehensive income/(loss), for the periods presented:
| March 31, 2018 |  | December 31, 2017
(dollars in thousands) | Gross Unrealized Gains |  |  | Gross Unrealized Losses |  |  | Net Unrealized Gains/ (Losses) |  |  | Gross Unrealized Gains |  |  | Gross Unrealized Losses |  |  | Net Unrealized Gains/ (Losses) |
Total unrealized gains(losses) on debt securities available-for-sale | $ | 3,070 |  |  | $ | (10,867 | ) |  | $ | (7,797 | ) |  | $ | 5,645 |  |  | $ | (3,967 | ) |  | $ | 1,678 |
Income tax (expense)benefit | (652 | ) |  | 2,308 |  |  | 1,656 |  |  | (1,982 | ) |  | 1,393 |  |  | (589 | )
Net Unrealized Gains/(losses), Net of Tax Included in Accumulated Other Comprehensive Income/(Loss) | $ | 2,418 |  |  | $ | (8,559 | ) |  | $ | (6,141 | ) |  | $ | 3,663 |  |  | $ | (2,574 | ) |  | $ | 1,089 |
Contractual Maturity of Debt Securities Available-for-Sale Securities | The amortized cost and fair value of debt securities available-for-sale at March 31, 2018 by contractual maturity are included in the table below. Actual maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations with or without call or prepayment penalties.
| March 31, 2018
(dollars in thousands) | Amortized Cost |  |  | Fair Value |
Obligations of the U.S. Treasury, U.S. government corporations and agencies, and obligations of states and political subdivisions |  |  |
Due in one year or less | $ | 43,472 |  |  | $ | 43,372 |
Due after one year through five years | 148,616 |  |  | 148,787 |
Due after five years through ten years | 78,565 |  |  | 78,767 |
Due after ten years | 28,792 |  |  | 29,465 |
| 299,445 |  |  | 300,391 |
Collateralized mortgage obligations of U.S. government corporations and agencies | 105,063 |  |  | 102,582 |
Residential mortgage-backed securities of U.S. government corporations and agencies | 30,700 |  |  | 30,683 |
Commercial mortgage-backed securities of U.S. government corporations and agencies | 255,043 |  |  | 248,798 |
Total Debt Securities Available-for-Sale | $ | 690,251 |  |  | $ | 682,454 |
Unrealized Gains and Losses on Marketable Securities | The following table presents realized and unrealized net gains and losses for our marketable equity securities for the periods presented:
| Three months ended March 31,
(dollars in thousands) | 2018 |  |  | 2017 |
Marketable Equity Securities |  |  |
Net gains/losses recognized during the period | $ | 52 |  |  | $ | 733 |
Less: Net gains/losses recognized for equity securities sold during the period | — |  |  | 370 |
Unrealized Gains/Losses Recognized on Equity Securities Still Held | $ | 52 |  |  | $ | 363 |

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