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Investment Securities (Schedule of Investment Securities Available for Sale) (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 9,748,355	$ 9,507,041
Gross Unrealized Gains	22,475	8,376
Gross Unrealized Losses	(312,417)	(414,001)
Carrying Value	9,458,413	9,101,416
Investments	9,467,082	9,130,244
U.S. Treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	175,307	214,796
Gross Unrealized Gains	1,035	165
Gross Unrealized Losses	(7,625)	(12,009)
Carrying Value	168,717	202,952
U.S. Government agency and sponsored enterprise residential MBS
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,699,845	2,672,554
Gross Unrealized Gains	12,055	3,607
Gross Unrealized Losses	(16,398)	(26,471)
Carrying Value	2,695,502	2,649,690
U.S. Government agency and sponsored enterprise commercial MBS
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	571,192	557,489
Gross Unrealized Gains	565	156
Gross Unrealized Losses	(45,032)	(61,892)
Carrying Value	526,725	495,753
Private label residential MBS and CMOs
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,562,963	2,491,033
Gross Unrealized Gains	2,439	506
Gross Unrealized Losses	(209,197)	(253,493)
Carrying Value	2,356,205	2,238,046
Private label commercial MBS
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,277,909	1,822,881
Gross Unrealized Gains	4,792	1,836
Gross Unrealized Losses	(22,321)	(40,688)
Carrying Value	2,260,380	1,784,029
Single family real estate-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	229,293	335,047
Gross Unrealized Gains	329	108
Gross Unrealized Losses	(2,541)	(8,074)
Carrying Value	227,081	327,081
Collateralized loan obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	988,160	1,131,088
Gross Unrealized Gains	747	1,804
Gross Unrealized Losses	(552)	(193)
Carrying Value	988,355	1,132,699
Non-mortgage asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	68,711	96,865
Gross Unrealized Gains	249	144
Gross Unrealized Losses	(1,062)	(2,555)
Carrying Value	67,898	94,454
State and municipal obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	111,421	110,388
Gross Unrealized Gains	238	13
Gross Unrealized Losses	(5,894)	(6,391)
Carrying Value	105,765	104,010
SBA securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	63,554	74,900
Gross Unrealized Gains	26	37
Gross Unrealized Losses	(1,795)	(2,235)
Carrying Value	61,785	72,702
Marketable equity securities
Debt Securities, Available-for-sale [Line Items]
Marketable equity securities	$ 8,669	$ 28,828

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