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INVESTMENT SECURITIES (Details) - USD ($) $ in Thousands | Sep. 30, 2016 | Dec. 31, 2015
--- | --- | ---
Schedule of Available-for-sale Securities |  |
Amortized Cost | $ 3,224,807 | $ 3,783,829
Gross Unrealized Gains | 21,463 | 11,744
Gross Unrealized Losses | (9,646) | (22,347)
Available-for-sale investment securities, at fair value | 3,236,624 | 3,773,226
Schedule of Held-to-maturity Security |  |
Amortized Cost | 154,461 | 0
Fair Value | 154,296 |
Investment Securities |  |
Amortized Cost | 3,379,268 |
Gross Unrealized Gains | 21,463 |
Gross Unrealized Losses | (9,811) |
Fair Value | 3,390,920 |
U.S. Treasury securities |  |
Schedule of Available-for-sale Securities |  |
Amortized Cost | 455,019 | 1,002,874
Gross Unrealized Gains | 1,440 | 33
Gross Unrealized Losses | (11) | (4,392)
Available-for-sale investment securities, at fair value | 456,448 | 998,515
U.S. government agency and U.S. government sponsored enterprise debt securities |  |
Schedule of Available-for-sale Securities |  |
Amortized Cost | 381,986 | 771,288
Gross Unrealized Gains | 1,386 | 555
Gross Unrealized Losses | (41) | (2,994)
Available-for-sale investment securities, at fair value | 383,331 | 768,849
U.S. government agency and U.S. government sponsored enterprise mortgage-backed securities - Commercial mortgage-backed securities |  |
Schedule of Available-for-sale Securities |  |
Amortized Cost | 325,486 | 354,418
Gross Unrealized Gains | 2,791 | 268
Gross Unrealized Losses | (1,459) | (3,024)
Available-for-sale investment securities, at fair value | 326,818 | 351,662
U.S. government agency and U.S. government sponsored enterprise mortgage-backed securities - Residential mortgage-backed securities |  |
Schedule of Available-for-sale Securities |  |
Amortized Cost | 1,188,753 | 996,255
Gross Unrealized Gains | 8,538 | 7,542
Gross Unrealized Losses | (2,453) | (6,401)
Available-for-sale investment securities, at fair value | 1,194,838 | 997,396
Municipal securities |  |
Schedule of Available-for-sale Securities |  |
Amortized Cost | 149,008 | 173,785
Gross Unrealized Gains | 3,423 | 2,657
Gross Unrealized Losses | (138) | (793)
Available-for-sale investment securities, at fair value | 152,293 | 175,649
Non-agency residential mortgage-backed securities | Investment grade |  |
Schedule of Available-for-sale Securities |  |
Amortized Cost | 51,396 | 62,133
Gross Unrealized Gains | 1,578 | 433
Gross Unrealized Losses | (17) | (173)
Available-for-sale investment securities, at fair value | 52,957 | 62,393
Corporate debt securities | Investment grade |  |
Schedule of Available-for-sale Securities |  |
Amortized Cost | 282,106 | 280,850
Gross Unrealized Gains | 533 | 129
Gross Unrealized Losses | (652) | (1,547)
Available-for-sale investment securities, at fair value | 281,987 | 279,432
Corporate debt securities | Non-investment grade |  |
Schedule of Available-for-sale Securities |  |
Amortized Cost | 10,191 | 11,491
Gross Unrealized Gains | 0 | 0
Gross Unrealized Losses | (1,413) | (1,849)
Available-for-sale investment securities, at fair value | 8,778 | 9,642
Foreign bonds | Investment grade |  |
Schedule of Available-for-sale Securities |  |
Amortized Cost | 340,474 | 90,586
Gross Unrealized Gains | 419 | 3
Gross Unrealized Losses | (3,459) | (794)
Available-for-sale investment securities, at fair value | 337,434 | 89,795
Foreign bonds | Multilateral development bank | Investment grade |  |
Schedule of Available-for-sale Securities |  |
Available-for-sale investment securities, at fair value | 296,800 | 49,700
Other securities |  |
Schedule of Available-for-sale Securities |  |
Amortized Cost | 40,388 | 40,149
Gross Unrealized Gains | 1,355 | 124
Gross Unrealized Losses | (3) | (380)
Available-for-sale investment securities, at fair value | 41,740 | $ 39,893
Non-agency commercial mortgage-backed security |  |
Schedule of Held-to-maturity Security |  |
Amortized Cost | 154,461 |
Gross Unrealized Gains | 0 |
Gross Unrealized Losses | (165) |
Fair Value | $ 154,296 |

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