Allowance for Credit Losses - Loan Balances by Year of Origination and Performing and Nonperforming Status (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	$ 952,159	$ 1,380,130
Year two	1,250,192	772,783
Year three	614,941	961,071
Year four	782,546	606,970
Year five	474,779	431,724
More than five years	1,608,076	1,591,979
Revolving	1,387,431	1,226,925
Revolving-Term	26,792	28,408
Total	7,096,916	6,999,990
Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	952,159	1,380,089
Year two	1,250,056	771,819
Year three	614,200	940,641
Year four	781,286	602,938
Year five	472,729	421,125
More than five years	1,590,910	1,564,501
Revolving	1,386,920	1,224,949
Revolving-Term	25,879	27,638
Total	7,074,139	6,933,699
Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	41
Year two	136	964
Year three	741	20,430
Year four	1,260	4,032
Year five	2,050	10,599
More than five years	17,166	27,478
Revolving	511	1,976
Revolving-Term	913	770
Total	22,777	66,291
Commercial Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	5,239,648	5,406,584
Commercial Loans | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	228,599	385,347
Year two	366,573	317,359
Year three	279,472	468,720
Year four	454,921	334,743
Year five	273,477	266,019
More than five years	938,489	881,391
Revolving	21,051	36,948
Revolving-Term	0	0
Total	2,562,582	2,690,528
Commercial Loans | Commercial real estate | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	228,599	385,347
Year two	366,573	317,359
Year three	279,472	461,613
Year four	454,441	332,482
Year five	273,477	259,723
More than five years	931,136	865,567
Revolving	21,051	36,948
Revolving-Term	0	0
Total	2,554,749	2,659,039
Commercial Loans | Commercial real estate | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0
Year three	0	7,107
Year four	480	2,261
Year five	0	6,296
More than five years	7,353	15,824
Revolving	0	0
Revolving-Term	0	0
Total	7,833	31,488
Commercial Loans | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	185,389	437,529
Year two	308,442	126,371
Year three	97,811	134,417
Year four	89,270	86,912
Year five	70,268	41,422
More than five years	146,865	136,470
Revolving	603,834	550,402
Revolving-Term	0	0
Total	1,501,879	1,513,523
Commercial Loans | Commercial and industrial | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	185,389	437,529
Year two	308,442	126,371
Year three	97,811	123,944
Year four	89,270	86,852
Year five	70,214	38,540
More than five years	146,814	136,427
Revolving	603,604	548,622
Revolving-Term	0	0
Total	1,501,544	1,498,285
Commercial Loans | Commercial and industrial | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	0
Year three	0	10,473
Year four	0	60
Year five	54	2,882
More than five years	51	43
Revolving	230	1,780
Revolving-Term	0	0
Total	335	15,239
Commercial Loans | Commercial construction
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	83,458	142,321
Year two	171,331	110,562
Year three	43,840	113,532
Year four	38,514	16,838
Year five	4,331	989
More than five years	5,047	10,477
Revolving	28,758	30,036
Revolving-Term	0	0
Total	375,279	424,755
Commercial Loans | Commercial construction | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	83,458	142,321
Year two	171,331	110,562
Year three	43,840	111,445
Year four	38,514	16,838
Year five	4,331	989
More than five years	4,663	10,093
Revolving	28,758	30,036
Revolving-Term	0	0
Total	374,895	422,284
Commercial Loans | Commercial construction | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	0
Year three	0	2,087
Year four	0	0
Year five	0	0
More than five years	384	384
Revolving	0	0
Revolving-Term	0	0
Total	384	2,471
Commercial Loans | Business banking
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	213,494	257,409
Year two	240,779	108,048
Year three	94,289	144,976
Year four	119,394	115,228
Year five	92,528	81,889
More than five years	307,630	318,735
Revolving	108,141	108,230
Revolving-Term	1,348	1,179
Total	1,177,603	1,135,693
Commercial Loans | Business banking | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	213,494	257,368
Year two	240,779	107,984
Year three	94,289	144,689
Year four	119,050	113,820
Year five	90,907	81,195
More than five years	303,348	311,673
Revolving	108,039	108,202
Revolving-Term	1,252	1,122
Total	1,171,158	1,126,052
Commercial Loans | Business banking | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	41
Year two	0	64
Year three	0	287
Year four	344	1,408
Year five	1,621	694
More than five years	4,282	7,062
Revolving	102	28
Revolving-Term	96	57
Total	6,445	9,641
Consumer Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	1,857,268	1,593,406
Consumer Loans | Business banking
Financing Receivable, Credit Quality Indicator [Line Items]
Total		357,900
Consumer Loans | Consumer real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	224,092	137,465
Year two	151,021	100,995
Year three	93,140	92,165
Year four	76,389	50,156
Year five	32,776	40,384
More than five years	209,197	238,462
Revolving	542,184	443,406
Revolving-Term	24,166	24,552
Total	1,352,965	1,127,585
Consumer Loans | Consumer real estate | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	224,092	137,465
Year two	150,885	100,253
Year three	92,672	91,689
Year four	75,953	49,853
Year five	32,401	39,657
More than five years	204,232	234,297
Revolving	542,005	443,238
Revolving-Term	23,352	23,839
Total	1,345,592	1,120,291
Consumer Loans | Consumer real estate | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	136	742
Year three	468	476
Year four	436	303
Year five	375	727
More than five years	4,965	4,165
Revolving	179	168
Revolving-Term	814	713
Total	7,373	7,294
Consumer Loans | Other Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	17,127	20,059
Year two	12,046	9,448
Year three	6,389	7,261
Year four	4,058	3,093
Year five	1,399	1,021
More than five years	848	6,444
Revolving	83,463	57,903
Revolving-Term	1,278	2,677
Total	126,608	107,906
Consumer Loans | Other Consumer | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	17,127	20,059
Year two	12,046	9,290
Year three	6,116	7,261
Year four	4,058	3,093
Year five	1,399	1,021
More than five years	717	6,444
Revolving	83,463	57,903
Revolving-Term	1,275	2,677
Total	126,201	107,748
Consumer Loans | Other Consumer | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	158
Year three	273	0
Year four	0	0
Year five	0	0
More than five years	131	0
Revolving	0	0
Revolving-Term	3	0
Total	$ 407	$ 158