Investment Securities (Schedule of Investment Securities Available for Sale) (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Dec. 31, 2025
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 9,594,139	$ 9,525,046
Gross Unrealized Gains	22,149	26,722
Gross Unrealized Losses	(304,426)	(293,851)
Carrying Value	9,311,862	9,257,917
Investments	9,317,614	9,263,651
U.S. Treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	318,809	275,966
Gross Unrealized Gains	183	530
Gross Unrealized Losses	(11,315)	(7,843)
Carrying Value	307,677	268,653
U.S. Government agency and sponsored enterprise residential MBS
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,227,612	2,562,702
Gross Unrealized Gains	14,691	16,003
Gross Unrealized Losses	(12,928)	(15,678)
Carrying Value	2,229,375	2,563,027
U.S. Government agency and sponsored enterprise commercial MBS
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	796,610	576,295
Gross Unrealized Gains	623	975
Gross Unrealized Losses	(46,533)	(42,907)
Carrying Value	750,700	534,363
Private label residential MBS and CMOs
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,727,024	2,683,881
Gross Unrealized Gains	1,393	2,505
Gross Unrealized Losses	(202,253)	(195,558)
Carrying Value	2,526,164	2,490,828
Private label commercial MBS
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,380,423	2,182,983
Gross Unrealized Gains	4,858	5,018
Gross Unrealized Losses	(20,921)	(19,891)
Carrying Value	2,364,360	2,168,110
Single family real estate-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	184,725	227,711
Gross Unrealized Gains	0	158
Gross Unrealized Losses	(1,930)	(1,977)
Carrying Value	182,795	225,892
Collateralized loan obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	773,119	780,847
Gross Unrealized Gains	203	1,315
Gross Unrealized Losses	(1,266)	(1,218)
Carrying Value	772,056	780,944
Non-mortgage asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	57,483	59,942
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(985)	(1,177)
Carrying Value	56,498	58,765
State and municipal obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	74,326	115,193
Gross Unrealized Gains	166	192
Gross Unrealized Losses	(4,789)	(5,865)
Carrying Value	69,703	109,520
SBA securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	54,008	59,526
Gross Unrealized Gains	32	26
Gross Unrealized Losses	(1,506)	(1,737)
Carrying Value	52,534	57,815
Marketable equity securities
Debt Securities, Available-for-sale [Line Items]
Marketable equity securities	$ 5,752	$ 5,734

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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