Loans and Allowance for Credit Losses - Schedule of Changes in Allowance for Loan Losses by Loan Category (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 224,310	$ 149,190	$ 228,952	$ 148,993
Charge-offs	(3,400)	(1,692)	(15,887)	(9,707)
Recoveries	3,603	2,522	4,848	3,283
Provision (release)	7,600	6,126	14,200	13,577
Ending balance	232,113	156,146	232,113	156,146
Commercial and industrial | Commercial Portfolio Segment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	46,490	28,863	41,090	26,959
Charge-offs	(82)	0	(82)	0
Recoveries	7	56	18	81
Provision (release)	7,695	(3)	13,084	1,876
Ending balance	54,110	28,916	54,110	28,916
Commercial real estate | Commercial Portfolio Segment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	106,634	64,629	116,175	65,475
Charge-offs	(1,790)	0	(13,377)	(7,250)
Recoveries	2,368	2,011	3,062	2,143
Provision (release)	(2,122)	2,439	(770)	8,711
Ending balance	105,090	69,079	105,090	69,079
Commercial construction | Commercial Portfolio Segment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	8,514	6,204	8,462	6,666
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision (release)	812	184	864	(278)
Ending balance	9,326	6,388	9,326	6,388
Business banking | Commercial Portfolio Segment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	20,315	14,631	19,899	14,913
Charge-offs	(999)	(1,002)	(1,341)	(1,104)
Recoveries	942	199	1,264	609
Provision (release)	427	2,920	863	2,330
Ending balance	20,685	16,748	20,685	16,748
Residential real estate | Residential Real Estate
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	31,096	25,935	32,291	25,954
Charge-offs	0	0	0	(10)
Recoveries	36	27	75	58
Provision (release)	349	(133)	(885)	(173)
Ending balance	31,481	25,829	31,481	25,829
Consumer home equity | Consumer Portfolio Segment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	6,891	5,684	7,472	5,595
Charge-offs	0	(32)	0	(34)
Recoveries	5	91	5	91
Provision (release)	184	38	(397)	129
Ending balance	7,080	5,781	7,080	5,781
Other Consumer | Consumer Portfolio Segment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	4,370	3,244	3,563	3,431
Charge-offs	(529)	(658)	(1,087)	(1,309)
Recoveries	245	138	424	301
Provision (release)	255	681	1,441	982
Ending balance	$ 4,341	$ 3,405	$ 4,341	$ 3,405