Regulatory Capital - Adjusted Transition Amounts (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020	Jan. 01, 2020
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Retained earnings	$ 2,913,544	$ 2,817,134			$ 952,639
Allowance for credit losses					1,143,053
Liability for unfunded commitments	32,707	72,713	$ 19,367	$ 110,044	115,758
Deferred tax asset					306,171
Accounting Standards Update 2016-13
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Liability for unfunded commitments					116,000
Deferred tax asset					$ 306,000
Adjustments | Accounting Standards Update 2016-13
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Retained earnings	(209,088)	(58,429)		(57,859)
Allowance for credit losses	(259,536)	(49,097)		(55,811)
Liability for unfunded commitments	(26,094)	(9,333)		(2,048)
Deferred tax asset	(76,542)	$ 0		$ 0
Adjusted Transition Amounts | Accounting Standards Update 2016-13
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Retained earnings	627,263
Allowance for credit losses	778,609
Liability for unfunded commitments	78,283
Deferred tax asset	$ 229,629