Investment Securities Available for Sale - Summary Of Available For Sale Investment Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 11,091,254	$ 11,273,327
Gross Unrealized Gains	31,540	2,560
Gross Unrealized Losses	(1,334,132)	(1,597,784)
Fair Value	9,788,662	9,678,103
Accrued interest receivable on investment securities available for sale	$ 26,600	$ 22,700
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other assets	Other assets
U.S. Treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 588,082	$ 515,953
Gross Unrealized Gains	9,547	0
Gross Unrealized Losses	0	(44,140)
Fair Value	597,629	471,813
U.S. Government agency securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	29,993	52,411
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1,053)	(3,613)
Fair Value	28,940	48,798
Mortgage-backed securities issued by U.S. Government agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,021,612	904,593
Gross Unrealized Gains	2,037	1,624
Gross Unrealized Losses	(97,985)	(113,468)
Fair Value	925,664	792,749
Mortgage-backed securities issued by U.S. Government sponsored enterprises
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	7,523,399	8,144,374
Gross Unrealized Gains	1,192	936
Gross Unrealized Losses	(1,094,212)	(1,250,240)
Fair Value	6,430,379	6,895,070
Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	692,487	769,498
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(104,892)	(114,371)
Fair Value	587,595	655,127
Commercial mortgage-backed securities issued by U.S. Government agencies or sponsored enterprises
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,226,672	877,590
Gross Unrealized Gains	18,764	0
Gross Unrealized Losses	(35,653)	(71,645)
Fair Value	1,209,783	805,945
Corporate debt securities and other debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	9,009	8,908
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(337)	(307)
Fair Value	$ 8,672	$ 8,601

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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