Loans and Allowance for Credit Losses - Activity in the Allowance for Loan Losses, by Portfolio Segment, for the Current Year (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	$ 205,332
Provision for credit losses	(19,914)	$ 1,445
Balance, end of period	178,924
Loans, Excluding Acquired Loans
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	205,332	238,050
Provision for credit losses	(19,914)	0
Charge-offs	(8,138)	(4,251)
Recoveries	1,644	1,317
Net charge-offs	(6,494)	(2,934)
Balance, end of period	178,924	235,116
Loans, Excluding Acquired Loans | Other Consumer and Other
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	4,617	5,617
Provision for credit losses	874	(2,715)
Charge-offs	(414)	(702)
Recoveries	387	304
Net charge-offs	(27)	(398)
Balance, end of period	5,464	2,504
Loans, Excluding Acquired Loans | Commercial
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	17,458	42,093
Provision for credit losses	(2,519)	(6,940)
Charge-offs	(6,319)	(859)
Recoveries	557	320
Net charge-offs	(5,762)	(539)
Balance, end of period	9,177	34,614
Loans, Excluding Acquired Loans | Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	179,270	182,868
Provision for credit losses	(17,822)	14,242
Charge-offs	(485)	(1,687)
Recoveries	426	403
Net charge-offs	(59)	(1,284)
Balance, end of period	161,389	195,826
Loans, Excluding Acquired Loans | Consumer | Credit cards
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	3,987	7,472
Provision for credit losses	(447)	(4,587)
Charge-offs	(920)	(1,003)
Recoveries	274	290
Net charge-offs	(646)	(713)
Balance, end of period	$ 2,894	$ 2,172