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		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period			$ 205,332
Provision for credit loss expense	$ 30,406	$ (10,011)	10,492	$ (10,011)
Balance, end of period	212,611		212,611
Loans, Excluding Acquired Loans
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	178,924	235,116	205,332	238,050
Acquisition adjustment for PCD loans	4,043		4,043
Provision for credit loss expense	30,406	(10,011)	10,492	(10,011)
Charge-offs	(2,334)	(2,205)	(10,463)	(6,456)
Recoveries	1,572	4,339	3,207	5,656
Net charge-offs	(762)	2,134	(7,256)	(800)
Balance, end of period	212,611	227,239	212,611	227,239
Loans, Excluding Acquired Loans | Other Consumer and Other
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	5,464	2,485	4,617	5,617
Provision for credit loss expense	1,454	1,117	2,328	(1,617)
Charge-offs	(518)	(411)	(932)	(1,113)
Recoveries	302	425	689	729
Net charge-offs	(216)	14	(243)	(384)
Balance, end of period	6,704	3,616	6,704	3,616
Loans, Excluding Acquired Loans | Commercial
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	9,177	34,633	17,458	42,093
Acquisition adjustment for PCD loans	854		854
Provision for credit loss expense	22,853	(6,678)	20,334	(13,599)
Charge-offs	(688)	(309)	(7,007)	(1,168)
Recoveries	621	2,147	1,178	2,467
Net charge-offs	(67)	1,838	(5,829)	1,299
Balance, end of period	32,817	29,793	32,817	29,793
Loans, Excluding Acquired Loans | Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	161,389	195,826	179,270	182,868
Acquisition adjustment for PCD loans	3,187		3,187
Provision for credit loss expense	1,629	(8,522)	(16,193)	5,720
Charge-offs	(124)	(439)	(600)	(2,126)
Recoveries	400	1,523	817	1,926
Net charge-offs	276	1,084	217	(200)
Balance, end of period	166,481	188,388	166,481	188,388
Loans, Excluding Acquired Loans | Consumer | Credit cards
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	2,894	2,172	3,987	7,472
Acquisition adjustment for PCD loans	0		0
Provision for credit loss expense	4,470	4,072	4,023	(515)
Charge-offs	(1,004)	(1,046)	(1,924)	(2,049)
Recoveries	249	244	523	534
Net charge-offs	(755)	(802)	(1,401)	(1,515)
Balance, end of period	6,609	$ 5,442	6,609	$ 5,442
Loans, Excluding Acquired Loans | Consumer | Other Consumer and Other
Allowance for Loan and Lease Losses [Roll Forward]
Acquisition adjustment for PCD loans	$ 2		$ 2