Securities (Schedule of Available-for-sale Debt Securities) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Schedule of Available-for-sale Debt Securities
Amortized Cost	$ 3,823,714	$ 3,320,648
Gross Unrealized Gains	90,565	19,805
Gross Unrealized Losses	(29,705)	(23,239)
AFS debt securities	3,884,574	3,317,214
U.S. Treasury securities
Schedule of Available-for-sale Debt Securities
Amortized Cost	250,494	177,215
Gross Unrealized Gains	707	0
Gross Unrealized Losses	0	(793)
AFS debt securities	251,201	176,422
U.S. government agency and U.S. government-sponsored enterprise debt securities
Schedule of Available-for-sale Debt Securities
Amortized Cost	433,923	584,275
Gross Unrealized Gains	8,853	1,377
Gross Unrealized Losses	(132)	(4,407)
AFS debt securities	442,644	581,245
U.S. government agency and U.S. government-sponsored enterprise mortgage-backed securities - Commercial mortgage-backed securities
Schedule of Available-for-sale Debt Securities
Amortized Cost	827,929	599,814
Gross Unrealized Gains	34,585	8,551
Gross Unrealized Losses	(4,074)	(4,894)
AFS debt securities	858,440	603,471
U.S. government agency and U.S. government-sponsored enterprise mortgage-backed securities - Residential mortgage-backed securities
Schedule of Available-for-sale Debt Securities
Amortized Cost	1,246,609	998,447
Gross Unrealized Gains	34,445	6,927
Gross Unrealized Losses	(159)	(1,477)
AFS debt securities	1,280,895	1,003,897
Municipal securities
Schedule of Available-for-sale Debt Securities
Amortized Cost	208,333	101,621
Gross Unrealized Gains	7,002	790
Gross Unrealized Losses	(151)	(109)
AFS debt securities	215,184	102,302
Non-agency commercial mortgage-backed securities
Schedule of Available-for-sale Debt Securities
Amortized Cost	148,322	86,609
Gross Unrealized Gains	3,989	1,947
Gross Unrealized Losses	(943)	(6)
AFS debt securities	151,368	88,550
Non-agency residential mortgage-backed securities
Schedule of Available-for-sale Debt Securities
Amortized Cost	113,548	46,830
Gross Unrealized Gains	804	3
Gross Unrealized Losses	(14)	(285)
AFS debt securities	114,338	46,548
Corporate debt securities
Schedule of Available-for-sale Debt Securities
Amortized Cost	31,254	11,250
Gross Unrealized Gains	74	12
Gross Unrealized Losses	(502)	(113)
AFS debt securities	30,826	11,149
Foreign bonds
Schedule of Available-for-sale Debt Securities
Amortized Cost	204,540	354,481
Gross Unrealized Gains	106	198
Gross Unrealized Losses	(566)	(507)
AFS debt securities	204,080	354,172
Asset-backed securities
Schedule of Available-for-sale Debt Securities
Amortized Cost	64,762	66,106
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(3,143)	(1,354)
AFS debt securities	61,619	64,752
Collateralized loan obligations (“CLOs”)
Schedule of Available-for-sale Debt Securities
Amortized Cost	294,000	294,000
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(20,021)	(9,294)
AFS debt securities	$ 273,979	$ 284,706

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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