Securities (Continuous Unrealized Losses) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Available-for-sale debt securities, Less than 12 Months, Fair Value	$ 1,519,603	$ 1,388,661
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(15,456)	(18,990)
Available-for-sale debt securities, More than 12 Months, Fair Value	342,859	351,048
Available-for-sale debt securities, Gross Unrealized Loss, More than 12 Months	(7,005)	(4,249)
Available-for-sale debt securities, Fair Value, Total	1,862,462	1,739,709
Available-for-sale debt securities, Gross Unrealized Loss, Total	(22,461)	(23,239)
U.S. Treasury securities
Debt Securities, Available-for-sale [Line Items]
Available-for-sale debt securities, Less than 12 Months, Fair Value		0
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months		0
Available-for-sale debt securities, More than 12 Months, Fair Value		176,422
Available-for-sale debt securities, Gross Unrealized Loss, More than 12 Months		(793)
Available-for-sale debt securities, Fair Value, Total		176,422
Available-for-sale debt securities, Gross Unrealized Loss, Total		(793)
U.S. government agency and U.S. government-sponsored enterprise debt securities
Debt Securities, Available-for-sale [Line Items]
Available-for-sale debt securities, Less than 12 Months, Fair Value	352,521	310,349
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(1,260)	(4,407)
Available-for-sale debt securities, More than 12 Months, Fair Value	0	0
Available-for-sale debt securities, Gross Unrealized Loss, More than 12 Months	0	0
Available-for-sale debt securities, Fair Value, Total	352,521	310,349
Available-for-sale debt securities, Gross Unrealized Loss, Total	(1,260)	(4,407)
US government agencies And U.S. government-sponsored enterprise mortgage-backed securities - Commercial mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Available-for-sale debt securities, Less than 12 Months, Fair Value	292,596	204,675
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(5,656)	(2,346)
Available-for-sale debt securities, More than 12 Months, Fair Value	3,543	108,314
Available-for-sale debt securities, Gross Unrealized Loss, More than 12 Months	(54)	(2,548)
Available-for-sale debt securities, Fair Value, Total	296,139	312,989
Available-for-sale debt securities, Gross Unrealized Loss, Total	(5,710)	(4,894)
US government agencies And U.S. government-sponsored enterprise mortgage-backed securities - Residential mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Available-for-sale debt securities, Less than 12 Months, Fair Value	342,561	325,354
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(1,611)	(1,234)
Available-for-sale debt securities, More than 12 Months, Fair Value	0	34,337
Available-for-sale debt securities, Gross Unrealized Loss, More than 12 Months	0	(243)
Available-for-sale debt securities, Fair Value, Total	342,561	359,691
Available-for-sale debt securities, Gross Unrealized Loss, Total	(1,611)	(1,477)
Municipal securities
Debt Securities, Available-for-sale [Line Items]
Available-for-sale debt securities, Less than 12 Months, Fair Value	24,529	31,130
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(88)	(109)
Available-for-sale debt securities, More than 12 Months, Fair Value	0	0
Available-for-sale debt securities, Gross Unrealized Loss, More than 12 Months	0	0
Available-for-sale debt securities, Fair Value, Total	24,529	31,130
Available-for-sale debt securities, Gross Unrealized Loss, Total	(88)	(109)
Non-agency commercial mortgage-backed Securities
Debt Securities, Available-for-sale [Line Items]
Available-for-sale debt securities, Less than 12 Months, Fair Value	58,738	7,914
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(1,230)	(6)
Available-for-sale debt securities, More than 12 Months, Fair Value	7,920	0
Available-for-sale debt securities, Gross Unrealized Loss, More than 12 Months	0	0
Available-for-sale debt securities, Fair Value, Total	66,658	7,914
Available-for-sale debt securities, Gross Unrealized Loss, Total	(1,230)	(6)
Non-agency residential mortgage-backed Securities
Debt Securities, Available-for-sale [Line Items]
Available-for-sale debt securities, Less than 12 Months, Fair Value	90,156	42,894
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(506)	(285)
Available-for-sale debt securities, More than 12 Months, Fair Value	0	0
Available-for-sale debt securities, Gross Unrealized Loss, More than 12 Months	0	0
Available-for-sale debt securities, Fair Value, Total	90,156	42,894
Available-for-sale debt securities, Gross Unrealized Loss, Total	(506)	(285)
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Available-for-sale debt securities, Less than 12 Months, Fair Value	251,674	0
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(3,645)	0
Available-for-sale debt securities, More than 12 Months, Fair Value	9,798	9,888
Available-for-sale debt securities, Gross Unrealized Loss, More than 12 Months	(203)	(113)
Available-for-sale debt securities, Fair Value, Total	261,472	9,888
Available-for-sale debt securities, Gross Unrealized Loss, Total	(3,848)	(113)
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Available-for-sale debt securities, Less than 12 Months, Fair Value	0	52,565
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	0	(902)
Available-for-sale debt securities, More than 12 Months, Fair Value	34,104	12,187
Available-for-sale debt securities, Gross Unrealized Loss, More than 12 Months	(242)	(452)
Available-for-sale debt securities, Fair Value, Total	34,104	64,752
Available-for-sale debt securities, Gross Unrealized Loss, Total	(242)	(1,354)
Collateralized loan obligations (“CLOs”)
Debt Securities, Available-for-sale [Line Items]
Available-for-sale debt securities, Less than 12 Months, Fair Value	0	284,706
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	0	(9,294)
Available-for-sale debt securities, More than 12 Months, Fair Value	287,494	0
Available-for-sale debt securities, Gross Unrealized Loss, More than 12 Months	(6,506)	0
Available-for-sale debt securities, Fair Value, Total	287,494	284,706
Available-for-sale debt securities, Gross Unrealized Loss, Total	(6,506)	(9,294)
Foreign Government Debt
Debt Securities, Available-for-sale [Line Items]
Available-for-sale debt securities, Less than 12 Months, Fair Value		129,074
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months		(407)
Available-for-sale debt securities, More than 12 Months, Fair Value		9,900
Available-for-sale debt securities, Gross Unrealized Loss, More than 12 Months		(100)
Available-for-sale debt securities, Fair Value, Total		138,974
Available-for-sale debt securities, Gross Unrealized Loss, Total		$ (507)
Foreign government bonds
Debt Securities, Available-for-sale [Line Items]
Available-for-sale debt securities, Less than 12 Months, Fair Value	106,828
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months	(1,460)
Available-for-sale debt securities, More than 12 Months, Fair Value	0
Available-for-sale debt securities, Gross Unrealized Loss, More than 12 Months	0
Available-for-sale debt securities, Fair Value, Total	106,828
Available-for-sale debt securities, Gross Unrealized Loss, Total	$ (1,460)

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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