Loans and Allowance for Credit Losses for Loans - Summary of Provision for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Receivables [Abstract]
Provision (credit) for loan losses	$ 3,496	$ 30,833	$ 17,998	$ 105,709
Provision for unfunded credit commitments	0	187	3,289	350
Total provision for credit losses for loans	$ 3,496	$ 31,020	$ 21,287	$ 106,059