Allowance for Credit Losses - Loan Balances by Year of Origination and Internally Assigned Risk Rating (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	$ 1,380,130	$ 1,360,684
Year two	772,783	1,214,746
Year three	961,071	831,734
Year four	606,970	565,201
Year five	431,724	610,556
More than five years	1,591,979	1,572,826
Revolving	1,226,925	1,041,199
Revolving-Term	28,408	28,914
Total	6,999,990	7,225,860
Commercial | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	385,347	334,086
Year two	317,359	476,203
Year three	468,720	417,944
Year four	334,743	320,140
Year five	266,019	415,184
More than five years	881,391	780,560
Revolving	36,948	47,830
Revolving-Term	0	0
Total	2,690,528	2,791,947
Commercial | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	437,529	457,828
Year two	126,371	215,457
Year three	134,417	145,290
Year four	86,912	82,249
Year five	41,422	28,488
More than five years	136,470	221,609
Revolving	550,402	408,631
Revolving-Term	0	0
Total	1,513,523	1,559,552
Commercial | Commercial construction
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	142,321	132,813
Year two	110,562	230,907
Year three	113,532	63,535
Year four	16,838	2,921
Year five	989	6,346
More than five years	10,477	16,777
Revolving	30,036	12,778
Revolving-Term	0	0
Total	424,755	466,077
Commercial | Business banking
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	257,409	296,357
Year two	108,048	156,473
Year three	144,976	128,250
Year four	115,228	91,363
Year five	81,889	82,202
More than five years	318,735	298,779
Revolving	108,230	105,549
Revolving-Term	1,179	1,094
Total	1,135,693	1,160,067
Commercial | Pass | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	385,347	334,086
Year two	316,003	422,800
Year three	412,191	394,963
Year four	314,303	277,724
Year five	213,019	307,321
More than five years	698,992	615,217
Revolving	35,448	46,330
Revolving-Term	0	0
Total	2,375,303	2,398,441
Commercial | Pass | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	437,483	454,131
Year two	126,371	199,453
Year three	115,359	140,049
Year four	83,030	68,607
Year five	37,176	27,645
More than five years	132,182	206,782
Revolving	536,554	383,082
Revolving-Term	0	0
Total	1,468,155	1,479,749
Commercial | Pass | Commercial construction
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	142,321	131,235
Year two	108,405	224,794
Year three	111,512	59,649
Year four	16,838	2,420
Year five	989	6,346
More than five years	3,539	4,555
Revolving	30,036	12,778
Revolving-Term	0	0
Total	413,640	441,777
Commercial | Pass | Business banking
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	257,264	296,254
Year two	107,791	154,335
Year three	141,411	123,207
Year four	110,586	86,552
Year five	79,187	77,238
More than five years	293,215	266,042
Revolving	107,093	103,571
Revolving-Term	443	291
Total	1,096,990	1,107,490
Commercial | Special Mention | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	35,499
Year three	37,786	10,200
Year four	6,401	22,502
Year five	40,445	55,174
More than five years	75,938	75,022
Revolving	0	0
Revolving-Term	0	0
Total	160,570	198,397
Commercial | Special Mention | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	46	3,697
Year two	0	8,211
Year three	3,060	2,628
Year four	2,546	697
Year five	72	768
More than five years	832	1,046
Revolving	8,887	23,527
Revolving-Term	0	0
Total	15,443	40,574
Commercial | Special Mention | Commercial construction
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	1,578
Year two	0	2,533
Year three	0	3,886
Year four	0	0
Year five	0	0
More than five years	4,458	8,593
Revolving	0	0
Revolving-Term	0	0
Total	4,458	16,590
Commercial | Special Mention | Business banking
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	104	0
Year two	151	1,060
Year three	1,986	1,147
Year four	1,365	1,602
Year five	1,057	1,084
More than five years	5,929	6,866
Revolving	160	637
Revolving-Term	111	123
Total	10,863	12,519
Commercial | Substandard | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	1,356	17,259
Year three	18,743	12,781
Year four	14,039	19,914
Year five	12,555	50,700
More than five years	106,461	83,792
Revolving	1,500	1,500
Revolving-Term	0	0
Total	154,654	185,946
Commercial | Substandard | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	7,793
Year three	14,221	2,613
Year four	1,336	8,544
Year five	4,174	75
More than five years	3,456	13,781
Revolving	4,961	2,022
Revolving-Term	0	0
Total	28,148	34,828
Commercial | Substandard | Commercial construction
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	2,157	3,580
Year three	2,020	0
Year four	0	501
Year five	0	0
More than five years	2,480	3,629
Revolving	0	0
Revolving-Term	0	0
Total	6,657	7,710
Commercial | Substandard | Business banking
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	41	103
Year two	106	1,078
Year three	1,579	3,896
Year four	3,277	3,209
Year five	1,645	3,880
More than five years	19,591	25,871
Revolving	977	1,341
Revolving-Term	625	680
Total	27,841	40,058
Commercial | Doubtful | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	645
Year three	0	0
Year four	0	0
Year five	0	1,989
More than five years	0	6,529
Revolving	0	0
Revolving-Term	0	0
Total	0	9,163
Commercial | Doubtful | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	0
Year three	1,777	0
Year four	0	4,401
Year five	0	0
More than five years	0	0
Revolving	0	0
Revolving-Term	0	0
Total	1,777	4,401
Commercial | Doubtful | Commercial construction
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	0
Year three	0	0
Year four	0	0
Year five	0	0
More than five years	0	0
Revolving	0	0
Revolving-Term	0	0
Total	0	0
Commercial | Doubtful | Business banking
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	0
Year three	0	0
Year four	0	0
Year five	0	0
More than five years	0	0
Revolving	0	0
Revolving-Term	0	0
Total	0	0
Consumer | Consumer real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	137,465	120,736
Year two	100,995	122,544
Year three	92,165	69,931
Year four	50,156	65,133
Year five	40,384	76,254
More than five years	238,462	251,047
Revolving	443,406	439,020
Revolving-Term	24,552	22,667
Total	1,127,585	1,167,332
Consumer | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	20,059	18,864
Year two	9,448	13,162
Year three	7,261	6,784
Year four	3,093	3,395
Year five	1,021	2,082
More than five years	6,444	4,054
Revolving	57,903	27,391
Revolving-Term	2,677	5,153
Total	107,906	80,885
Consumer | Pass | Consumer real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	137,465	120,736
Year two	100,995	122,171
Year three	91,981	67,700
Year four	48,531	63,653
Year five	39,029	73,805
More than five years	231,861	243,939
Revolving	442,530	438,888
Revolving-Term	23,391	22,667
Total	1,115,783	1,153,559
Consumer | Pass | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	19,976	18,849
Year two	9,396	13,162
Year three	7,120	6,784
Year four	2,878	3,395
Year five	613	2,082
More than five years	2,037	687
Revolving	57,702	26,647
Revolving-Term	1,130	2,767
Total	100,852	74,373
Consumer | Special Mention | Consumer real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	0
Year three	0	1,489
Year four	0	0
Year five	0	0
More than five years	937	150
Revolving	0	132
Revolving-Term	0	0
Total	937	1,771
Consumer | Special Mention | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	0
Year three	0	0
Year four	0	0
Year five	0	0
More than five years	0	0
Revolving	0	0
Revolving-Term	0	0
Total	0	0
Consumer | Substandard | Consumer real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	373
Year three	184	742
Year four	1,625	1,480
Year five	1,355	2,449
More than five years	5,664	6,958
Revolving	876	0
Revolving-Term	1,161	0
Total	10,865	12,002
Consumer | Substandard | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	83	15
Year two	52	0
Year three	141	0
Year four	215	0
Year five	408	0
More than five years	4,407	3,367
Revolving	201	744
Revolving-Term	1,547	2,386
Total	7,054	6,512
Consumer | Doubtful | Consumer real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	0
Year three	0	0
Year four	0	0
Year five	0	0
More than five years	0	0
Revolving	0	0
Revolving-Term	0	0
Total	0	0
Consumer | Doubtful | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Year two	0	0
Year three	0	0
Year four	0	0
Year five	0	0
More than five years	0	0
Revolving	0	0
Revolving-Term	0	0
Total	$ 0	$ 0