Commitments and Contingencies - Commitments and Letters of Credit (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Other Commitments [Line Items]
Commitments and letters of credit	$ 2,560,825	$ 2,671,292
Commitments to extend credit
Other Commitments [Line Items]
Commitments and letters of credit	2,481,275	2,583,957
Standby letters of credit
Other Commitments [Line Items]
Commitments and letters of credit	$ 79,550	$ 87,335