| Investment Securities |
Investment Securities
The following tables present the amortized cost, the gross unrealized gains and losses and the fair value of the Company’s investment securities: | | | | | | | | | | | | | | | December 31, 2015 | | Amortized Cost | | Gross Unrealized | | Fair Value | (Dollars in thousands) | | Gains | | Losses | | Available-for-sale | | | | | | | | U.S. government and federal agency | $ | 47,868 |
| | 15 |
| | (432 | ) | | 47,451 |
| U.S. government sponsored enterprises | 93,230 |
| | 100 |
| | (163 | ) | | 93,167 |
| State and local governments | 856,738 |
| | 34,159 |
| | (5,878 | ) | | 885,019 |
| Corporate bonds | 386,629 |
| | 611 |
| | (3,077 | ) | | 384,163 |
| Residential mortgage-backed securities | 1,203,548 |
| | 6,180 |
| | (8,768 | ) | | 1,200,960 |
| Total available-for-sale | 2,588,013 |
| | 41,065 |
| | (18,318 | ) | | 2,610,760 |
| Held-to-maturity | | | | | | | | State and local governments | 702,072 |
| | 31,863 |
| | (4,422 | ) | | 729,513 |
| Total held-to-maturity | 702,072 |
| | 31,863 |
| | (4,422 | ) | | 729,513 |
| Total investment securities | $ | 3,290,085 |
| | 72,928 |
| | (22,740 | ) | | 3,340,273 |
|
| | | | | | | | | | | | | | | December 31, 2014 | | Amortized Cost | | Gross Unrealized | | Fair Value | (Dollars in thousands) | | Gains | | Losses | | Available-for-sale | | | | | | | | U.S. government and federal agency | $ | 44 |
| | — |
| | — |
| | 44 |
| U.S. government sponsored enterprises | 21,916 |
| | 31 |
| | (2 | ) | | 21,945 |
| State and local governments | 962,365 |
| | 40,173 |
| | (4,569 | ) | | 997,969 |
| Corporate bonds | 313,545 |
| | 2,059 |
| | (750 | ) | | 314,854 |
| Residential mortgage-backed securities | 1,043,897 |
| | 11,205 |
| | (2,486 | ) | | 1,052,616 |
| Total available-for-sale | 2,341,767 |
| | 53,468 |
| | (7,807 | ) | | 2,387,428 |
| Held-to-maturity | | | | | | | | State and local governments | 520,997 |
| | 32,925 |
| | (2,976 | ) | | 550,946 |
| Total held-to-maturity | 520,997 |
| | 32,925 |
| | (2,976 | ) | | 550,946 |
| Total investment securities | $ | 2,862,764 |
| | 86,393 |
| | (10,783 | ) | | 2,938,374 |
|
Note 2. Investment Securities (continued)
The following table presents the amortized cost and fair value of available-for-sale and held-to-maturity securities by contractual maturity at December 31, 2015. Actual maturities may differ from expected or contractual maturities since issuers have the right to prepay obligations with or without prepayment penalties. | | | | | | | | | | | | | | | December 31, 2015 | | Available-for-Sale | | Held-to-Maturity | (Dollars in thousands) | Amortized Cost | | Fair Value | | Amortized Cost | | Fair Value | Due within one year | $ | 140,703 |
| | 141,230 |
| | — |
| | — |
| Due after one year through five years | 486,235 |
| | 484,467 |
| | — |
| | — |
| Due after five years through ten years | 128,158 |
| | 131,883 |
| | 25,073 |
| | 25,605 |
| Due after ten years | 629,369 |
| | 652,220 |
| | 676,999 |
| | 703,908 |
| | 1,384,465 |
| | 1,409,800 |
| | 702,072 |
| | 729,513 |
| Residential mortgage-backed securities 1 | 1,203,548 |
| | 1,200,960 |
| | — |
| | — |
| Total | $ | 2,588,013 |
| | 2,610,760 |
| | 702,072 |
| | 729,513 |
|
________ 1 Residential mortgage-backed securities, which have prepayment provisions, are not assigned to maturity categories due to fluctuations in their prepayment speeds.
Proceeds from sales and calls of investment securities and the associated gains and losses that have been included in earnings are listed below: | | | | | | | | | | | | Years ended | (Dollars in thousands) | December 31,
2015 | | December 31,
2014 | | December 31,
2013 | Available-for-sale | | | | | | Proceeds from sales and calls of investment securities | $ | 167,660 |
| | 219,849 |
| | 181,971 |
| Gross realized gains 1 | 1,877 |
| | 501 |
| | 3,723 |
| Gross realized losses 1 | (1,808 | ) | | (705 | ) | | (4,022 | ) | Held-to-maturity | | | | | | Proceeds from calls of investment securities | 20,997 |
| | 8,930 |
| | — |
| Gross realized gains 1 | 50 |
| | 22 |
| | — |
| Gross realized losses 1 | (100 | ) | | (6 | ) | | — |
|
__________ 1 The gain or loss on the sale or call of each investment security is determined by the specific identification method.
At December 31, 2015 and 2014, the Company had investment securities with carrying values of $1,824,819,000 and $1,673,263,000, respectively, pledged as collateral for FHLB advances, FRB discount window borrowings, repurchase agreements, interest rate swap agreements and deposits of several local government units. Note 2. Investment Securities (continued)
Investment securities with an unrealized loss position are summarized as follows: | | | | | | | | | | | | | | | | | | | | | December 31, 2015 | | Less than 12 Months | | 12 Months or More | | Total | (Dollars in thousands) | Fair Value | | Unrealized Loss | | Fair Value | | Unrealized Loss | | Fair Value | | Unrealized Loss | Available-for-sale | | | | | | | | | | | | U.S. government and federal agency | $ | 42,493 |
| | (432 | ) | | 2 |
| | — |
| | 42,495 |
| | (432 | ) | U.S. government sponsored enterprises | 60,010 |
| | (163 | ) | | — |
| | — |
| | 60,010 |
| | (163 | ) | State and local governments | 102,422 |
| | (1,629 | ) | | 115,943 |
| | (4,249 | ) | | 218,365 |
| | (5,878 | ) | Corporate bonds | 228,258 |
| | (1,812 | ) | | 13,962 |
| | (1,265 | ) | | 242,220 |
| | (3,077 | ) | Residential mortgage-backed securities | 730,412 |
| | (7,226 | ) | | 53,021 |
| | (1,542 | ) | | 783,433 |
| | (8,768 | ) | Total available-for-sale | $ | 1,163,595 |
| | (11,262 | ) | | 182,928 |
| | (7,056 | ) | | 1,346,523 |
| | (18,318 | ) | Held-to-maturity | | | | | | | | | | | | State and local governments | $ | 42,322 |
| | (594 | ) | | 81,709 |
| | (3,828 | ) | | 124,031 |
| | (4,422 | ) | Total held-to-maturity | $ | 42,322 |
| | (594 | ) | | 81,709 |
| | (3,828 | ) | | 124,031 |
| | (4,422 | ) |
| | | | | | | | | | | | | | | | | | | | | December 31, 2014 | | Less than 12 Months | | 12 Months or More | | Total | (Dollars in thousands) | Fair Value | | Unrealized Loss | | Fair Value | | Unrealized Loss | | Fair Value | | Unrealized Loss | Available-for-sale | | | | | | | | | | | | U.S. government and federal agency | $ | — |
| | — |
| | 3 |
| | — |
| | 3 |
| | — |
| U.S. government sponsored enterprises | 13,793 |
| | (2 | ) | | — |
| | — |
| | 13,793 |
| | (2 | ) | State and local governments | 91,082 |
| | (1,273 | ) | | 115,927 |
| | (3,296 | ) | | 207,009 |
| | (4,569 | ) | Corporate bonds | 60,289 |
| | (545 | ) | | 7,874 |
| | (205 | ) | | 68,163 |
| | (750 | ) | Residential mortgage-backed securities | 192,962 |
| | (926 | ) | | 78,223 |
| | (1,560 | ) | | 271,185 |
| | (2,486 | ) | Total available-for-sale | $ | 358,126 |
| | (2,746 | ) | | 202,027 |
| | (5,061 | ) | | 560,153 |
| | (7,807 | ) | Held-to-maturity | | | | | | | | | | | | State and local governments | $ | 18,643 |
| | (624 | ) | | 76,761 |
| | (2,352 | ) | | 95,404 |
| | (2,976 | ) | Total held-to-maturity | $ | 18,643 |
| | (624 | ) | | 76,761 |
| | (2,352 | ) | | 95,404 |
| | (2,976 | ) |
Based on an analysis of its investment securities with unrealized losses as of December 31, 2015 and 2014, the Company determined that none of such securities had other-than-temporary impairment and the unrealized losses were primarily the result of interest rate changes and market spreads subsequent to acquisition. The fair value of the investment securities is expected to recover as payments are received and the securities approach maturity. At December 31, 2015, management determined that it did not intend to sell investment securities with unrealized losses, and there was no expected requirement to sell any of its investment securities with unrealized losses before recovery of their amortized cost. |