Securities (Continuous Unrealized Losses) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Schedule of Available-for-sale Debt Securities
Available-for-sale debt securities, Less than 12 Months, Fair Value	$ 5,715,518	$ 1,519,603
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(106,241)	(15,456)
Available-for-sale debt securities, 12 Months or More, Fair Value	873,339	342,859
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	(27,437)	(7,005)
Available-for-sale debt securities fair value, Total	6,588,857	1,862,462
Available-for-sale debt securities, Gross Unrealized Loss, Total	(133,678)	(22,461)
U.S. Treasury securities
Schedule of Available-for-sale Debt Securities
Available-for-sale debt securities, Less than 12 Months, Fair Value	768,909	352,521
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(8,769)	(1,260)
Available-for-sale debt securities, 12 Months or More, Fair Value	0	0
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	0	0
Available-for-sale debt securities fair value, Total	768,909	352,521
Available-for-sale debt securities, Gross Unrealized Loss, Total	(8,769)	(1,260)
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	1,008,979
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(21,747)
Available-for-sale debt securities, 12 Months or More, Fair Value	144,196
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	(5,781)
Available-for-sale debt securities fair value, Total	1,153,175
Available-for-sale debt securities, Gross Unrealized Loss, Total	(27,528)
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	603,554	292,596
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(17,164)	(5,656)
Available-for-sale debt securities, 12 Months or More, Fair Value	107,752	3,543
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	(5,421)	(54)
Available-for-sale debt securities fair value, Total	711,306	296,139
Available-for-sale debt securities, Gross Unrealized Loss, Total	(22,585)	(5,710)
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	1,904,559	342,561
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(35,792)	(1,611)
Available-for-sale debt securities, 12 Months or More, Fair Value	17,591	0
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	(1,130)	0
Available-for-sale debt securities fair value, Total	1,922,150	342,561
Available-for-sale debt securities, Gross Unrealized Loss, Total	(36,922)	(1,611)
Municipal securities
Schedule of Available-for-sale Debt Securities
Available-for-sale debt securities, Less than 12 Months, Fair Value	249,055	24,529
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(7,612)	(88)
Available-for-sale debt securities, 12 Months or More, Fair Value	0	0
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	0	0
Available-for-sale debt securities fair value, Total	249,055	24,529
Available-for-sale debt securities, Gross Unrealized Loss, Total	(7,612)	(88)
Non-agency commercial mortgage-backed securities
Schedule of Available-for-sale Debt Securities
Available-for-sale debt securities, Less than 12 Months, Fair Value	151,915	58,738
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(2,158)	(1,230)
Available-for-sale debt securities, 12 Months or More, Fair Value	40,233	7,920
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	(1,134)	0
Available-for-sale debt securities fair value, Total	192,148	66,658
Available-for-sale debt securities, Gross Unrealized Loss, Total	(3,292)	(1,230)
Non-agency residential mortgage-backed securities
Schedule of Available-for-sale Debt Securities
Available-for-sale debt securities, Less than 12 Months, Fair Value	561,635	90,156
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(3,233)	(506)
Available-for-sale debt securities, 12 Months or More, Fair Value	8,145	0
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	(3)	0
Available-for-sale debt securities fair value, Total	569,780	90,156
Available-for-sale debt securities, Gross Unrealized Loss, Total	(3,236)	(506)
Corporate debt securities
Schedule of Available-for-sale Debt Securities
Available-for-sale debt securities, Less than 12 Months, Fair Value	207,861	251,674
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(6,139)	(3,645)
Available-for-sale debt securities, 12 Months or More, Fair Value	178,833	9,798
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	(11,166)	(203)
Available-for-sale debt securities fair value, Total	386,694	261,472
Available-for-sale debt securities, Gross Unrealized Loss, Total	(17,305)	(3,848)
Foreign government bonds
Schedule of Available-for-sale Debt Securities
Available-for-sale debt securities, Less than 12 Months, Fair Value	54,228	106,828
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(3,514)	(1,460)
Available-for-sale debt securities, 12 Months or More, Fair Value	84,977	0
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	(414)	0
Available-for-sale debt securities fair value, Total	139,205	106,828
Available-for-sale debt securities, Gross Unrealized Loss, Total	(3,928)	(1,460)
Asset-backed securities
Schedule of Available-for-sale Debt Securities
Available-for-sale debt securities, Less than 12 Months, Fair Value	21,631	0
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(55)	0
Available-for-sale debt securities, 12 Months or More, Fair Value	0	34,104
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	0	(242)
Available-for-sale debt securities fair value, Total	21,631	34,104
Available-for-sale debt securities, Gross Unrealized Loss, Total	(55)	(242)
Collateralized loan obligations (“CLOs”)
Schedule of Available-for-sale Debt Securities
Available-for-sale debt securities, Less than 12 Months, Fair Value	183,192	0
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(58)	0
Available-for-sale debt securities, 12 Months or More, Fair Value	291,612	287,494
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	(2,388)	(6,506)
Available-for-sale debt securities fair value, Total	474,804	287,494
Available-for-sale debt securities, Gross Unrealized Loss, Total	$ (2,446)	$ (6,506)

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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