Investment Securities - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($) security	Dec. 31, 2020 USD ($) security	Dec. 31, 2019 USD ($)
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Pledged securities not separately reported	$ 80,810,000	$ 70,570,000
HTM debt securities transferred	438,000
Transferred securities sold	378,000
Gain (loss) from sale of transferred securities	58,000
Debt securities, held-to-maturity, allowance for credit loss	0	3,000
Allowance for credit losses on available-for-sale investment securities	$ 2,000	0
Percentage of investment portfolio considered investment grade	99.00%
Marketable Securities, Gain (Loss), Excluding Other-than-temporary Impairment Loss			$ 1,000
Gross pre-tax unrealized losses	$ 1,046,000	$ 123,000
Number of securities in loss position | security	954	503
Agency MBS
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Debt securities, available-for-sale, transferred security, at carrying value	$ 1,250,000	$ 8,600,000	3,980
Debt securities, available-for-sale, unrealized loss	12,000	120,000	49,000
ABS and municipal bonds
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Securities sold	12,820,000	2,650,000	5,640,000
Pre-tax gain (loss) on sale of securities	57,000	4,000	$ 1,000
Held-to-maturity under money market mutual fund liquidity facility
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Debt securities, held-to-maturity, allowance for credit loss	$ 0	$ 1,000
Minimum | Agency MBS
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Debt securities, available-for-sale, securities transferred, Security Term	1 year
Maximum | Agency MBS
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Debt securities, available-for-sale, securities transferred, Security Term	36 years