Allowance for Credit Losses - Activity in ACL by Class of Loans and Leases (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	$ 143,900	$ 157,262
Charge-offs	(5,830)	(4,858)
Recoveries	2,616	2,259
Provision	6,436	(4,383)
Balance at end of year	147,122	150,280
Commercial Lending
Rollforward of the Allowance for Credit Losses
Charge-offs	(791)
Commercial and Industrial
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	14,564	20,080
Charge-offs	(791)	(706)
Recoveries	246	53
Provision	19	(267)
Balance at end of year	14,038	19,160
Commercial real estate
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	43,810	42,951
Recoveries		14
Provision	(3,499)	2,273
Balance at end of year	40,311	45,238
Construction
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	5,843	9,773
Provision	630	(865)
Balance at end of year	6,473	8,908
Lease financing
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	1,551	1,659
Provision	(70)	(297)
Balance at end of year	1,481	1,362
Residential mortgage
Rollforward of the Allowance for Credit Losses
Charge-offs	(257)
Residential mortgage | Residential Lending: Residential Mortgage
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	35,175	34,364
Charge-offs	(122)
Recoveries	27	16
Provision	(760)	(3,492)
Balance at end of year	34,320	30,888
Residential mortgage | Home equity line
Rollforward of the Allowance for Credit Losses
Charge-offs	(135)
Home equity line | Home equity line
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	8,296	5,642
Charge-offs	(135)	(43)
Recoveries	177	28
Provision	1,003	(543)
Balance at end of year	9,341	5,084
Consumer Portfolio Segment [Member]
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	34,661	42,793
Charge-offs	(4,782)	(4,109)
Recoveries	2,166	2,148
Provision	9,113	(1,192)
Balance at end of year	$ 41,158	$ 39,640