Securities (Continuous Unrealized Losses) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Schedule of Available-for-sale Debt Securities
Available-for-sale debt securities, Less than 12 Months, Fair Value	$ 785,217	$ 163,128
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(2,290)	(1,518)
Available-for-sale debt securities, 12 Months or More, Fair Value	524,008	2,087,534
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	(5,779)	(69,249)
Available-for-sale debt securities Fair Value, Total	1,309,225	2,250,662
Available-for-sale debt securities, Gross Unrealized Loss, Total	(8,069)	(70,767)
U.S. Treasury securities
Schedule of Available-for-sale Debt Securities
Available-for-sale debt securities, Less than 12 Months, Fair Value	199,711	0
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(76)	0
Available-for-sale debt securities, 12 Months or More, Fair Value	226,402	516,520
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	(1,346)	(12,899)
Available-for-sale debt securities Fair Value, Total	426,113	516,520
Available-for-sale debt securities, Gross Unrealized Loss, Total	(1,422)	(12,899)
U.S. government agency and U.S. government sponsored enterprise debt securities
Schedule of Available-for-sale Debt Securities
Available-for-sale debt securities, Less than 12 Months, Fair Value	354,916	22,755
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(85)	(238)
Available-for-sale debt securities, 12 Months or More, Fair Value	0	159,814
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	0	(2,456)
Available-for-sale debt securities Fair Value, Total	354,916	182,569
Available-for-sale debt securities, Gross Unrealized Loss, Total	(85)	(2,694)
U.S. government agency and U.S. government sponsored enterprise mortgage-backed securities - Commercial mortgage-backed securities
Schedule of Available-for-sale Debt Securities
Available-for-sale debt securities, Less than 12 Months, Fair Value	60,336	26,886
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(573)	(245)
Available-for-sale debt securities, 12 Months or More, Fair Value	116,139	274,666
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	(2,091)	(12,449)
Available-for-sale debt securities Fair Value, Total	176,475	301,552
Available-for-sale debt securities, Gross Unrealized Loss, Total	(2,664)	(12,694)
U.S. government agency and U.S. government sponsored enterprise mortgage-backed securities - Residential mortgage-backed securities
Schedule of Available-for-sale Debt Securities
Available-for-sale debt securities, Less than 12 Months, Fair Value	87,356	75,675
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(553)	(491)
Available-for-sale debt securities, 12 Months or More, Fair Value	43,403	653,660
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	(353)	(14,061)
Available-for-sale debt securities Fair Value, Total	130,759	729,335
Available-for-sale debt securities, Gross Unrealized Loss, Total	(906)	(14,552)
Municipal securities
Schedule of Available-for-sale Debt Securities
Available-for-sale debt securities, Less than 12 Months, Fair Value	979	9,458
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(1)	(104)
Available-for-sale debt securities, 12 Months or More, Fair Value	5,046	30,295
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	(6)	(928)
Available-for-sale debt securities Fair Value, Total	6,025	39,753
Available-for-sale debt securities, Gross Unrealized Loss, Total	(7)	(1,032)
Non-agency commercial mortgage-backed securities
Schedule of Available-for-sale Debt Securities
Available-for-sale debt securities, Less than 12 Months, Fair Value	7,914
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(6)
Available-for-sale debt securities, 12 Months or More, Fair Value	0
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	0
Available-for-sale debt securities Fair Value, Total	7,914
Available-for-sale debt securities, Gross Unrealized Loss, Total	(6)
Non-agency residential mortgage-backed securities
Schedule of Available-for-sale Debt Securities
Available-for-sale debt securities, Less than 12 Months, Fair Value	11,145	3,067
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(139)	(19)
Available-for-sale debt securities, 12 Months or More, Fair Value	0	3,949
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	0	(166)
Available-for-sale debt securities Fair Value, Total	11,145	7,016
Available-for-sale debt securities, Gross Unrealized Loss, Total	(139)	(185)
Corporate debt securities
Schedule of Available-for-sale Debt Securities
Available-for-sale debt securities, Less than 12 Months, Fair Value	1,247	10,869
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(3)	(381)
Available-for-sale debt securities, 12 Months or More, Fair Value	9,775	0
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	(225)	0
Available-for-sale debt securities Fair Value, Total	11,022	10,869
Available-for-sale debt securities, Gross Unrealized Loss, Total	(228)	(381)
Foreign bonds
Schedule of Available-for-sale Debt Securities
Available-for-sale debt securities, Less than 12 Months, Fair Value	14,338	14,418
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(101)	(40)
Available-for-sale debt securities, 12 Months or More, Fair Value	123,243	448,630
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	(1,758)	(26,290)
Available-for-sale debt securities Fair Value, Total	137,581	463,048
Available-for-sale debt securities, Gross Unrealized Loss, Total	(1,859)	$ (26,330)
Asset-backed securities
Schedule of Available-for-sale Debt Securities
Available-for-sale debt securities, Less than 12 Months, Fair Value	47,275
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(753)
Available-for-sale debt securities, 12 Months or More, Fair Value	0
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	0
Available-for-sale debt securities Fair Value, Total	47,275
Available-for-sale debt securities, Gross Unrealized Loss, Total	$ (753)

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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