Securities (Schedule of Available-for-sale Debt Securities) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Schedule of Available-for-sale Debt Securities
Total available-for-sale debt investment securities, Amortized Cost	$ 2,675,834	$ 2,806,900
Gross Unrealized Gains	7,230	5,714
Gross Unrealized Losses	(42,906)	(70,767)
Available-for-sale debt securities, Fair Value	2,640,158	2,741,847
U.S. Treasury securities
Schedule of Available-for-sale Debt Securities
Total available-for-sale debt investment securities, Amortized Cost	528,983	577,561
Gross Unrealized Gains	0	153
Gross Unrealized Losses	(8,543)	(12,899)
Available-for-sale debt securities, Fair Value	520,440	564,815
U.S. government agency and U.S. government sponsored enterprise debt securities
Schedule of Available-for-sale Debt Securities
Total available-for-sale debt investment securities, Amortized Cost	183,145	219,485
Gross Unrealized Gains	704	382
Gross Unrealized Losses	(1,313)	(2,694)
Available-for-sale debt securities, Fair Value	182,536	217,173
U.S. government agency and U.S. government sponsored enterprise mortgage-backed securities - Commercial mortgage-backed securities
Schedule of Available-for-sale Debt Securities
Total available-for-sale debt investment securities, Amortized Cost	433,435	420,486
Gross Unrealized Gains	2,408	811
Gross Unrealized Losses	(9,552)	(12,694)
Available-for-sale debt securities, Fair Value	426,291	408,603
U.S. government agency and U.S. government sponsored enterprise mortgage-backed securities - Residential mortgage-backed securities
Schedule of Available-for-sale Debt Securities
Total available-for-sale debt investment securities, Amortized Cost	890,126	957,219
Gross Unrealized Gains	3,021	4,026
Gross Unrealized Losses	(6,322)	(14,552)
Available-for-sale debt securities, Fair Value	886,825	946,693
Municipal securities
Schedule of Available-for-sale Debt Securities
Total available-for-sale debt investment securities, Amortized Cost	76,003	82,965
Gross Unrealized Gains	190	87
Gross Unrealized Losses	(189)	(1,032)
Available-for-sale debt securities, Fair Value	76,004	82,020
Non-agency commercial mortgage-backed securities
Schedule of Available-for-sale Debt Securities
Total available-for-sale debt investment securities, Amortized Cost	41,423	25,826
Gross Unrealized Gains	876	226
Gross Unrealized Losses	0	0
Available-for-sale debt securities, Fair Value	42,299	26,052
Non-agency residential mortgage-backed securities
Schedule of Available-for-sale Debt Securities
Total available-for-sale debt investment securities, Amortized Cost	9,518	10,109
Gross Unrealized Gains	21	7
Gross Unrealized Losses	(84)	(185)
Available-for-sale debt securities, Fair Value	9,455	9,931
Corporate debt securities
Schedule of Available-for-sale Debt Securities
Total available-for-sale debt investment securities, Amortized Cost	11,250	11,250
Gross Unrealized Gains	7	0
Gross Unrealized Losses	(163)	(381)
Available-for-sale debt securities, Fair Value	11,094	10,869
Foreign bonds
Schedule of Available-for-sale Debt Securities
Total available-for-sale debt investment securities, Amortized Cost	489,324	489,378
Gross Unrealized Gains	3	0
Gross Unrealized Losses	(16,658)	(26,330)
Available-for-sale debt securities, Fair Value	472,669	463,048
Asset-backed securities
Schedule of Available-for-sale Debt Securities
Total available-for-sale debt investment securities, Amortized Cost	12,627	12,621
Gross Unrealized Gains	0	22
Gross Unrealized Losses	(82)	0
Available-for-sale debt securities, Fair Value	$ 12,545	$ 12,643

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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