Investment Securities Available for Sale - Summary Of Available For Sale Investment Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 11,152,743	$ 11,091,254
Gross Unrealized Gains	7,464	31,540
Gross Unrealized Losses	(1,465,692)	(1,334,132)
Fair Value	9,694,515	9,788,662
Accrued interest receivable on investment securities available for sale	$ 28,700	$ 26,600
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	$ 616,037	$ 588,082
Gross Unrealized Gains	505	9,547
Gross Unrealized Losses	(1,133)	0
Fair Value	615,409	597,629
U.S. Government agency securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	29,993	29,993
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1,210)	(1,053)
Fair Value	28,783	28,940
Mortgage-backed securities issued by U.S. Government agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,022,881	1,021,612
Gross Unrealized Gains	1,119	2,037
Gross Unrealized Losses	(112,082)	(97,985)
Fair Value	911,918	925,664
Mortgage-backed securities issued by U.S. Government sponsored enterprises
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	7,383,405	7,523,399
Gross Unrealized Gains	328	1,192
Gross Unrealized Losses	(1,200,822)	(1,094,212)
Fair Value	6,182,911	6,430,379
Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	676,772	692,487
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(111,832)	(104,892)
Fair Value	564,940	587,595
Commercial mortgage-backed securities issued by U.S. Government agencies or sponsored enterprises
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,414,621	1,226,672
Gross Unrealized Gains	5,512	18,764
Gross Unrealized Losses	(38,403)	(35,653)
Fair Value	1,381,730	1,209,783
Corporate debt securities and other debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	9,034	9,009
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(210)	(337)
Fair Value	$ 8,824	$ 8,672