Regulatory Capital - Adjusted Transition Amounts (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021	Jan. 01, 2020
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Retained earnings	$ 3,250,478	$ 3,163,640
Allowance for credit losses	1,479,306	1,357,075	$ 1,227,362	$ 1,165,335
Liability for unfunded commitments	32,720	124,924	$ 32,707	72,713
Accounting Standards Update 2016-13
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Allowance for credit losses					$ 1,100,000
Liability for unfunded commitments					116,000
Deferred tax asset					$ 306,000
Adjusted Phase-In Amounts Remaining
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Retained earnings				836,351
Allowance for credit losses				1,038,145
Liability for unfunded commitments				104,377
Deferred tax asset				$ 306,171
Adjusted Phase-In Amounts Remaining | Accounting Standards Update 2016-13 | Remaining Adjusted Transition Amounts to be Phased-In
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Retained earnings	418,175
Allowance for credit losses	519,073
Liability for unfunded commitments	52,189
Deferred tax asset	153,087
Adjustments | Accounting Standards Update 2016-13
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Retained earnings	(209,088)	(209,088)
Allowance for credit losses	(259,536)	(259,536)
Liability for unfunded commitments	(26,094)	(26,094)
Deferred tax asset	$ (76,542)	$ (76,542)