Loans and Allowance for Credit Losses for Loans - Summary of Activity in Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Allowance for loan losses:
Beginning balance	$ 342,880	$ 283,342	$ 340,243	$ 161,759
Loans charged-off	(12,374)	(16,657)	(21,174)	(22,962)
Charged-off loans recovered	3,008	1,904	5,753	3,410
Net (charge-offs) recoveries	(9,366)	(14,753)	(15,421)	(19,552)
Provision (credit) for loan losses	5,810	41,025	14,502	74,876
Ending balance	339,324	309,614	339,324	309,614
Allowance for PCD loans reclassification		61,600		61,600
Cumulative Effect, Period of Adoption, Adjustment
Allowance for loan losses:
Beginning balance				92,531
Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for loan losses:
Beginning balance				254,290
Commercial and industrial
Allowance for loan losses:
Beginning balance	126,408	127,437	131,070	104,059
Loans charged-off	(10,893)	(14,024)	(18,035)	(17,384)
Charged-off loans recovered	678	799	2,267	1,368
Net (charge-offs) recoveries	(10,215)	(13,225)	(15,768)	(16,016)
Provision (credit) for loan losses	(6,504)	17,827	(5,613)	28,827
Ending balance	109,689	132,039	109,689	132,039
Commercial and industrial \| Cumulative Effect, Period of Adoption, Adjustment
Allowance for loan losses:
Beginning balance				15,169
Commercial and industrial \| Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for loan losses:
Beginning balance				119,228
Commercial Real Estate
Allowance for loan losses:
Beginning balance	174,236	111,585	164,113	45,673
Loans charged-off	0	(27)	(382)	(71)
Charged-off loans recovered	665	51	734	144
Net (charge-offs) recoveries	665	24	352	73
Provision (credit) for loan losses	14,238	20,093	24,674	36,159
Ending balance	189,139	131,702	189,139	131,702
Commercial Real Estate \| Cumulative Effect, Period of Adoption, Adjustment
Allowance for loan losses:
Beginning balance				49,797
Commercial Real Estate \| Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for loan losses:
Beginning balance				95,470
Residential Mortgage
Allowance for loan losses:
Beginning balance	27,172	29,456	28,873	5,060
Loans charged-off	(1)	(5)	(139)	(341)
Charged-off loans recovered	191	545	348	595
Net (charge-offs) recoveries	190	540	209	254
Provision (credit) for loan losses	(2,059)	(366)	(3,779)	3,741
Ending balance	25,303	29,630	25,303	29,630
Residential Mortgage \| Cumulative Effect, Period of Adoption, Adjustment
Allowance for loan losses:
Beginning balance				20,575
Residential Mortgage \| Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for loan losses:
Beginning balance				25,635
Consumer
Allowance for loan losses:
Beginning balance	15,064	14,864	16,187	6,967
Loans charged-off	(1,480)	(2,601)	(2,618)	(5,166)
Charged-off loans recovered	1,474	509	2,404	1,303
Net (charge-offs) recoveries	(6)	(2,092)	(214)	(3,863)
Provision (credit) for loan losses	135	3,471	(780)	6,149
Ending balance	$ 15,193	$ 16,243	$ 15,193	16,243
Consumer \| Cumulative Effect, Period of Adoption, Adjustment
Allowance for loan losses:
Beginning balance				6,990
Consumer \| Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for loan losses:
Beginning balance				$ 13,957

Amount excluding accrued interest, of allowance for credit loss on financing receivable.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 1
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