Allowance for Credit Losses - Activity in ACL by Class of Loans and Leases (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	$ 160,517	$ 148,581	$ 156,533	$ 143,900	$ 143,900
Charge-offs	(5,770)	(4,449)	(16,392)	(15,929)
Recoveries	1,837	4,739	6,151	9,464
Provision	7,116	5,924	17,408	17,360
Balance at end of year	163,700	154,795	163,700	154,795	156,533
Commercial Portfolio Segment [Member]
Rollforward of the Allowance for Credit Losses
Charge-offs			(3,164)		(5,982)
Commercial and Industrial
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	14,713	13,810	14,956	14,564	14,564
Charge-offs	(1,178)	(784)	(2,764)	(2,572)	(3,482)
Recoveries	160	2,637	621	3,175
Provision	(470)	(1,963)	412	(1,467)
Balance at end of year	13,225	13,700	13,225	13,700	14,956
Commercial Real Estate Portfolio Segment [Member]
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	44,412	39,887	43,944	43,810	43,810
Charge-offs	(400)		(400)		(2,500)
Provision	1	3,911	469	(12)
Balance at end of year	44,013	43,798	44,013	43,798	43,944
Construction
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	9,331	9,871	10,392	5,843	5,843
Provision	481	333	(580)	4,361
Balance at end of year	9,812	10,204	9,812	10,204	10,392
Finance Leases Portfolio Segment [Member]
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	2,352	1,447	1,754	1,551	1,551
Provision	(62)	263	536	159
Balance at end of year	2,290	1,710	2,290	1,710	1,754
Residential mortgage
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	46,152	32,803	36,880	35,175	35,175
Charge-offs				(122)	(414)
Recoveries	31	53	89	110
Provision	(3,287)	4,143	5,927	1,836
Balance at end of year	42,896	36,999	42,896	36,999	36,880
Residential mortgage | Residential Lending: Home Equity Line
Rollforward of the Allowance for Credit Losses
Charge-offs					(292)
Residential Lending: Home Equity Line
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	9,183	11,806	11,728	8,296	8,296
Charge-offs				(272)
Recoveries	86	303	242	539
Provision	1,268	(682)	(1,433)	2,864
Balance at end of year	10,537	11,427	10,537	11,427	11,728
Consumer
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	34,374	38,957	36,879	34,661	34,661
Charge-offs	(4,192)	(3,665)	(13,228)	(12,963)	(17,110)
Recoveries	1,560	1,746	5,199	5,640
Provision	9,185	(81)	12,077	9,619
Balance at end of year	$ 40,927	$ 36,957	$ 40,927	$ 36,957	$ 36,879