Allowance for Credit Losses - Activity in ACL by Class of Loans and Leases (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	$ 147,122	$ 150,280	$ 143,900	$ 157,262
Charge-offs	(5,650)	(5,022)	(11,480)	(9,880)
Recoveries	2,109	2,684	4,725	4,943
Provision	5,000	1,000	11,436	(3,383)
Balance at end of year	148,581	148,942	148,581	148,942
Commercial Lending
Rollforward of the Allowance for Credit Losses
Charge-offs			(1,788)
Commercial and Industrial
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	14,038	19,160	14,564	20,080
Charge-offs	(997)	(243)	(1,788)	(949)
Recoveries	292	301	538	354
Provision	477	(3,294)	496	(3,561)
Balance at end of year	13,810	15,924	13,810	15,924
Commercial real estate
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	40,311	45,238	43,810	42,951
Recoveries				14
Provision	(424)	(512)	(3,923)	1,761
Balance at end of year	39,887	44,726	39,887	44,726
Construction
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	6,473	8,908	5,843	9,773
Provision	3,398	(3,541)	4,028	(4,406)
Balance at end of year	9,871	5,367	9,871	5,367
Lease financing
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	1,481	1,362	1,551	1,659
Recoveries		60		60
Provision	(34)	(24)	(104)	(321)
Balance at end of year	1,447	1,398	1,447	1,398
Residential mortgage
Rollforward of the Allowance for Credit Losses
Charge-offs			(394)
Residential mortgage | Residential Lending: Residential Mortgage
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	34,320	30,888	35,175	34,364
Charge-offs			(122)
Recoveries	30	192	57	208
Provision	(1,547)	2,555	(2,307)	(937)
Balance at end of year	32,803	33,635	32,803	33,635
Residential mortgage | Home equity line
Rollforward of the Allowance for Credit Losses
Charge-offs			(272)
Home equity line | Home equity line
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	9,341	5,084	8,296	5,642
Charge-offs	(137)	(1,120)	(272)	(1,163)
Recoveries	59	191	236	219
Provision	2,543	579	3,546	36
Balance at end of year	11,806	4,734	11,806	4,734
Consumer Portfolio Segment [Member]
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	41,158	39,640	34,661	42,793
Charge-offs	(4,516)	(3,659)	(9,298)	(7,768)
Recoveries	1,728	1,940	3,894	4,088
Provision	587	5,237	9,700	4,045
Balance at end of year	$ 38,957	$ 43,158	$ 38,957	$ 43,158