Loans and Allowance for Credit Losses - Loan Balances by Year of Origination and Performing and Nonperforming Status (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	$ 851,275	$ 893,015
Year two	888,086	1,134,650
Year three	1,043,900	1,191,528
Year four	1,075,378	897,782
Year five	765,208	421,743
More than five years	1,977,472	1,885,462
Revolving	1,336,549	1,284,808
Revolving-Term	43,139	33,970
Total	7,981,007	7,742,958
Commercial loans \| Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	357,915	278,187
Year two	313,459	289,081
Year three	346,620	363,529
Year four	374,846	415,621
Year five	371,026	215,632
More than five years	1,144,311	1,110,490
Revolving	41,933	35,991
Revolving-Term	0	0
Total	2,950,110	2,708,531
Commercial loans \| Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	99,681	120,143
Year two	101,512	148,100
Year three	121,060	195,756
Year four	158,522	152,971
Year five	102,950	31,312
More than five years	181,586	197,426
Revolving	510,674	505,929
Revolving-Term	0	0
Total	1,275,985	1,351,637
Commercial loans \| Commercial construction
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	117,262	119,355
Year two	108,723	121,816
Year three	51,523	73,851
Year four	18,783	14,911
Year five	2,535	884
More than five years	1,315	2,139
Revolving	6,871	8,310
Revolving-Term	0	0
Total	307,012	341,266
Commercial loans \| Business banking
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	144,317	149,624
Year two	133,625	233,041
Year three	212,579	226,654
Year four	206,807	177,683
Year five	165,687	76,643
More than five years	358,287	345,327
Revolving	93,939	92,981
Revolving-Term	1,105	1,305
Total	1,316,346	1,303,258
Consumer loans \| Consumer real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	126,397	217,250
Year two	224,897	335,763
Year three	307,586	324,389
Year four	311,823	133,347
Year five	121,497	95,504
More than five years	290,644	229,462
Revolving	611,729	570,558
Revolving-Term	34,381	27,236
Total	2,028,954	1,933,509
Consumer loans \| Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	5,703	8,456
Year two	5,870	6,849
Year three	4,532	7,349
Year four	4,597	3,249
Year five	1,513	1,768
More than five years	1,329	618
Revolving	71,403	71,039
Revolving-Term	7,653	5,429
Total	$ 102,600	$ 104,757

Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease.

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