Securities (Continuous Unrealized Losses) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Schedule of Available-for-sale Debt Securities
Available-for-sale debt securities, Less than 12 Months, Fair Value	$ 5,031,239	$ 1,519,603
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(170,164)	(15,456)
Available-for-sale debt securities, 12 Months or More, Fair Value	320,850	342,859
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	(2,622)	(7,005)
Available-for-sale debt securities fair value, Total	5,352,089	1,862,462
Available-for-sale debt securities, Gross Unrealized Loss, Total	(172,786)	(22,461)
U.S. Treasury securities
Schedule of Available-for-sale Debt Securities
Available-for-sale debt securities, Less than 12 Months, Fair Value	775,801	352,521
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(15,697)	(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	775,801	352,521
Available-for-sale debt securities, Gross Unrealized Loss, Total	(15,697)	(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	954,894
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(47,586)
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	954,894
Available-for-sale debt securities, Gross Unrealized Loss, Total	(47,586)
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	615,193	292,596
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(25,203)	(5,656)
Available-for-sale debt securities, 12 Months or More, Fair Value	3,474	3,543
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	(51)	(54)
Available-for-sale debt securities fair value, Total	618,667	296,139
Available-for-sale debt securities, Gross Unrealized Loss, Total	(25,254)	(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	1,464,574	342,561
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(41,264)	(1,611)
Available-for-sale debt securities, 12 Months or More, Fair Value	358	0
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	(1)	0
Available-for-sale debt securities fair value, Total	1,464,932	342,561
Available-for-sale debt securities, Gross Unrealized Loss, Total	(41,265)	(1,611)
Municipal securities
Schedule of Available-for-sale Debt Securities
Available-for-sale debt securities, Less than 12 Months, Fair Value	199,225	24,529
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(4,959)	(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	199,225	24,529
Available-for-sale debt securities, Gross Unrealized Loss, Total	(4,959)	(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	114,971	58,738
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(4,374)	(1,230)
Available-for-sale debt securities, 12 Months or More, Fair Value	15,578	7,920
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	(9)	0
Available-for-sale debt securities fair value, Total	130,549	66,658
Available-for-sale debt securities, Gross Unrealized Loss, Total	(4,383)	(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	391,444	90,156
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(3,659)	(506)
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	391,444	90,156
Available-for-sale debt securities, Gross Unrealized Loss, Total	(3,659)	(506)
Corporate debt securities
Schedule of Available-for-sale Debt Securities
Available-for-sale debt securities, Less than 12 Months, Fair Value	347,934	251,674
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(25,316)	(3,645)
Available-for-sale debt securities, 12 Months or More, Fair Value	9,974	9,798
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	(27)	(203)
Available-for-sale debt securities fair value, Total	357,908	261,472
Available-for-sale debt securities, Gross Unrealized Loss, Total	(25,343)	(3,848)
Foreign government bonds
Schedule of Available-for-sale Debt Securities
Available-for-sale debt securities, Less than 12 Months, Fair Value	155,299	106,828
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(2,092)	(1,460)
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	155,299	106,828
Available-for-sale debt securities, Gross Unrealized Loss, Total	(2,092)	(1,460)
Asset-backed securities
Schedule of Available-for-sale Debt Securities
Available-for-sale debt securities, Less than 12 Months, Fair Value	11,904	0
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(14)	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	11,904	34,104
Available-for-sale debt securities, Gross Unrealized Loss, Total	(14)	(242)
Collateralized loan obligations (“CLOs”)
Schedule of Available-for-sale Debt Securities
Available-for-sale debt securities, Less than 12 Months, Fair Value	0	0
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	0	0
Available-for-sale debt securities, 12 Months or More, Fair Value	291,466	287,494
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More	(2,534)	(6,506)
Available-for-sale debt securities fair value, Total	291,466	287,494
Available-for-sale debt securities, Gross Unrealized Loss, Total	$ (2,534)	$ (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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