Fair Value Measurements - Activity for Level 3 Assets Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Level 3 CMO [Roll Forward]
Other Borrowings, Fair Value Disclosure	$ 128,375		$ 132,030
Total included in earnings	0	$ 104
Proceeds from (Repayments of) Debt	10,119,680	991,000
Unrealized net holding gains (losses) on securities available-for-sale arising during the period	67,971	$ (609,826)
Credit-Link Notes
Level 3 CMO [Roll Forward]
Other Borrowings, Fair Value Disclosure	128,375		$ 132,030
Level 3
Level 3 CMO [Roll Forward]
Equity warrants, Balance, beginning of period	4,048
Total included in earnings	(333)
Total included in other comprehensive income	0
Payments for Repurchase of Warrants	0
Sales, Equity Warrants	283
Fair Value, Assets, Level 2 to Level 1 Transfers, Amount	0
Warrant (loss) income	19
Fair Value, Equity, Transfers to Level 1, Amount	1
Level 3 | Credit-Link Notes
Level 3 CMO [Roll Forward]
Total included in earnings	(1,998)
Total included in other comprehensive income	0
Proceeds from Issuance of Debt	0
Proceeds from (Repayments of) Debt	$ (1,657)
Fair Value, Equity, Level 2 to Level 1 Transfers, Description
Debt Securities Exercises and Settlements	$ 0
Fair Value, Equity, Transfers to Level 1, Amount	0
Level 3 | Corporate Debt Securities
Level 3 CMO [Roll Forward]
Total included in earnings	0
Proceeds from Issuance of Debt	0
Proceeds from (Repayments of) Debt	$ 0
Fair Value, Equity, Level 2 to Level 1 Transfers, Description	18,000
Debt Securities Exercises and Settlements	$ 0
Fair Value, Measurements, Recurring
Level 3 CMO [Roll Forward]
Equity warrants, Balance, beginning of period	4,048
Equity warrants, Balance, end of period	3,978
Fair Value, Measurements, Recurring | Level 3
Level 3 CMO [Roll Forward]
Equity warrants, Balance, beginning of period	4,048
Equity warrants, Balance, end of period	3,978
Fair Value, Measurements, Recurring | Level 3 | Corporate Debt Securities
Level 3 CMO [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	14,779
Total included in other comprehensive income	(3,221)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	0
Asset-backed | Fair Value, Measurements, Recurring | Level 3
Level 3 CMO [Roll Forward]
Unrealized net holding gains (losses) on securities available-for-sale arising during the period	$ (3,221)