Loans and Allowance for Credit Losses - Loan Balances by Year of Origination and Performing and Nonperforming Status (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Dec. 31, 2025
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	$ 441,085	$ 1,166,736
Year two	1,229,953	890,701
Year three	851,627	995,373
Year four	907,563	988,809
Year five	893,329	722,161
More than five years	2,311,779	1,900,975
Revolving	1,369,013	1,362,700
Revolving-Term	54,037	44,502
Total	8,058,386	8,071,957
Commercial loans | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	136,999	480,967
Year two	479,147	315,684
Year three	336,323	326,048
Year four	292,910	319,652
Year five	276,039	343,726
More than five years	1,225,011	1,093,130
Revolving	37,889	42,554
Revolving-Term	0	0
Total	2,784,318	2,921,761
Commercial loans | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	142,993	161,634
Year two	153,924	96,065
Year three	88,302	115,559
Year four	106,585	139,784
Year five	119,285	93,561
More than five years	254,012	184,888
Revolving	542,933	539,114
Revolving-Term		0
Total	1,408,034	1,330,605
Commercial loans | Commercial construction
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	61,703	172,822
Year two	257,445	119,821
Year three	91,356	43,093
Year four	35,260	18,762
Year five	9,314	2,520
More than five years	2,795	1,260
Revolving	8,337	7,099
Revolving-Term	0	0
Total	466,210	365,377
Commercial loans | Business banking
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	56,851	182,401
Year two	173,803	132,590
Year three	122,530	206,281
Year four	188,163	199,780
Year five	192,035	161,293
More than five years	461,567	338,580
Revolving	93,236	93,856
Revolving-Term	948	1,082
Total	1,289,133	1,315,863
Consumer loans | Consumer real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	39,081	161,896
Year two	160,319	221,288
Year three	209,046	300,460
Year four	281,854	306,962
Year five	294,037	119,961
More than five years	367,067	281,990
Revolving	641,309	620,773
Revolving-Term	37,892	33,741
Total	2,030,605	2,047,071
Consumer loans | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	3,458	7,016
Year two	5,315	5,253
Year three	4,070	3,932
Year four	2,791	3,869
Year five	2,619	1,100
More than five years	1,327	1,127
Revolving	45,309	59,304
Revolving-Term	15,197	9,679
Total	$ 80,086	$ 91,280