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Allowance for Credit Losses - Loan Balances by Year of Origination and Internally Assigned Risk Rating (Details) - USD ($) $ in Thousands | Mar. 31, 2021 | Dec. 31, 2020
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Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | $ 435,060 | $ 1,360,684
2020 | 1,184,593 | 1,214,746
2019 | 1,197,397 | 831,734
2018 | 777,580 | 565,201
2017 | 517,769 | 610,556
2016 and Prior | 2,014,783 | 1,572,826
Revolving | 1,027,762 | 1,041,199
Revolving-Term | 28,225 | 28,914
Total | 7,183,168 | 7,225,860
Pass |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 429,585 | 1,355,291
2020 | 1,176,989 | 1,136,715
2019 | 1,098,741 | 792,352
2018 | 738,120 | 502,350
2017 | 462,653 | 494,436
2016 and Prior | 1,673,313 | 1,337,221
Revolving | 1,002,104 | 1,011,297
Revolving-Term | 24,770 | 25,726
Total | 6,606,275 | 6,655,389
Special mention |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 0 | 5,274
2020 | 7,532 | 47,302
2019 | 68,876 | 19,350
2018 | 13,283 | 24,802
2017 | 24,342 | 57,026
2016 and Prior | 133,387 | 91,677
Revolving | 18,005 | 24,296
Revolving-Term | 122 | 123
Total | 265,547 | 269,851
Substandard |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 5,476 | 118
2020 | 72 | 30,083
2019 | 29,134 | 20,032
2018 | 26,177 | 33,648
2017 | 30,773 | 57,105
2016 and Prior | 200,579 | 137,398
Revolving | 7,653 | 5,607
Revolving-Term | 3,332 | 3,066
Total | 303,198 | 287,056
Doubtful |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 0 | 0
2020 | 0 | 645
2019 | 645 | 0
2018 | 0 | 4,401
2017 | 0 | 1,989
2016 and Prior | 7,503 | 6,529
Revolving | 0 | 0
Revolving-Term | 0 | 0
Total | 8,148 | 13,564
Commercial |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 5,676,683 | 5,673,707
Commercial | Commercial real estate |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 96,988 | 334,086
2020 | 319,656 | 476,203
2019 | 497,992 | 417,944
2018 | 400,461 | 320,140
2017 | 300,796 | 415,184
2016 and Prior | 1,118,080 | 780,560
Revolving | 46,354 | 47,830
Revolving-Term | 0 | 0
Total | 2,780,327 | 2,791,947
Commercial | Commercial and industrial |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 257,902 | 457,828
2020 | 481,453 | 215,457
2019 | 203,334 | 145,290
2018 | 118,255 | 82,249
2017 | 61,054 | 28,488
2016 and Prior | 193,891 | 221,609
Revolving | 383,699 | 408,631
Revolving-Term | 0 | 0
Total | 1,699,588 | 1,559,552
Commercial | Commercial construction |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 24,730 | 132,813
2020 | 131,133 | 230,907
2019 | 202,255 | 63,535
2018 | 53,248 | 2,921
2017 | 2,560 | 6,346
2016 and Prior | 22,301 | 16,777
Revolving | 13,232 | 12,778
Revolving-Term | 0 | 0
Total | 449,459 | 466,077
Commercial | Business banking |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 34,568 | 296,357
2020 | 121,591 | 156,473
2019 | 171,003 | 128,250
2018 | 139,513 | 91,363
2017 | 93,638 | 82,202
2016 and Prior | 395,703 | 298,779
Revolving | 112,001 | 105,549
Revolving-Term | 1,061 | 1,094
Total | 1,069,078 | 1,160,067
Commercial | Pass | Commercial real estate |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 96,988 | 334,086
2020 | 319,206 | 422,800
2019 | 444,668 | 394,963
2018 | 376,347 | 277,724
2017 | 258,362 | 307,321
2016 and Prior | 850,342 | 615,217
Revolving | 44,872 | 46,330
Revolving-Term | 0 | 0
Total | 2,390,785 | 2,398,441
Commercial | Pass | Commercial and industrial |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 252,427 | 454,131
2020 | 478,363 | 199,453
2019 | 168,546 | 140,049
2018 | 110,278 | 68,607
2017 | 55,096 | 27,645
2016 and Prior | 179,887 | 206,782
Revolving | 361,828 | 383,082
Revolving-Term | 0 | 0
Total | 1,606,425 | 1,479,749
Commercial | Pass | Commercial construction |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 24,730 | 131,235
2020 | 127,643 | 224,794
2019 | 195,245 | 59,649
2018 | 53,248 | 2,420
2017 | 2,059 | 6,346
2016 and Prior | 10,856 | 4,555
Revolving | 13,232 | 12,778
Revolving-Term | 0 | 0
Total | 427,012 | 441,777
Commercial | Pass | Business banking |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 34,568 | 296,254
2020 | 121,017 | 154,335
2019 | 167,764 | 123,207
2018 | 134,358 | 86,552
2017 | 89,027 | 77,238
2016 and Prior | 362,534 | 266,042
Revolving | 110,572 | 103,571
Revolving-Term | 265 | 291
Total | 1,020,105 | 1,107,490
Commercial | Special mention | Commercial real estate |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 0 | 0
2020 | 450 | 35,499
2019 | 35,420 | 10,200
2018 | 8,342 | 22,502
2017 | 22,541 | 55,174
2016 and Prior | 113,614 | 75,022
Revolving | 0 | 0
Revolving-Term | 0 | 0
Total | 180,367 | 198,397
Commercial | Special mention | Commercial and industrial |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 0 | 3,697
2020 | 3,090 | 8,211
2019 | 28,623 | 2,628
2018 | 3,562 | 697
2017 | 180 | 768
2016 and Prior | 1,289 | 1,046
Revolving | 17,718 | 23,527
Revolving-Term | 0 | 0
Total | 54,461 | 40,574
Commercial | Special mention | Commercial construction |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 0 | 1,578
2020 | 3,490 | 2,533
2019 | 2,862 | 3,886
2018 | 0 | 0
2017 | 0 | 0
2016 and Prior | 8,478 | 8,593
Revolving | 0 | 0
Revolving-Term | 0 | 0
Total | 14,830 | 16,590
Commercial | Special mention | Business banking |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 0 | 0
2020 | 502 | 1,060
2019 | 1,972 | 1,147
2018 | 1,379 | 1,602
2017 | 1,621 | 1,084
2016 and Prior | 7,759 | 6,866
Revolving | 287 | 637
Revolving-Term | 122 | 123
Total | 13,642 | 12,519
Commercial | Substandard | Commercial real estate |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 0 | 0
2020 | 0 | 17,259
2019 | 17,259 | 12,781
2018 | 15,772 | 19,914
2017 | 19,894 | 50,700
2016 and Prior | 146,624 | 83,792
Revolving | 1,482 | 1,500
Revolving-Term | 0 | 0
Total | 201,030 | 185,946
Commercial | Substandard | Commercial and industrial |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 5,476 | 0
2020 | 0 | 7,793
2019 | 6,165 | 2,613
2018 | 4,415 | 8,544
2017 | 5,778 | 75
2016 and Prior | 12,715 | 13,781
Revolving | 4,153 | 2,022
Revolving-Term | 0 | 0
Total | 38,701 | 34,828
Commercial | Substandard | Commercial construction |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 0 | 0
2020 | 0 | 3,580
2019 | 4,148 | 0
2018 | 0 | 501
2017 | 501 | 0
2016 and Prior | 2,967 | 3,629
Revolving | 0 | 0
Revolving-Term | 0 | 0
Total | 7,616 | 7,710
Commercial | Substandard | Business banking |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 0 | 103
2020 | 72 | 1,078
2019 | 1,267 | 3,896
2018 | 3,777 | 3,209
2017 | 2,990 | 3,880
2016 and Prior | 25,409 | 25,871
Revolving | 1,141 | 1,341
Revolving-Term | 674 | 680
Total | 35,330 | 40,058
Commercial | Doubtful | Commercial real estate |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 0 | 0
2020 | 0 | 645
2019 | 645 | 0
2018 | 0 | 0
2017 | 0 | 1,989
2016 and Prior | 7,499 | 6,529
Revolving | 0 | 0
Revolving-Term | 0 | 0
Total | 8,144 | 9,163
Commercial | Doubtful | Commercial and industrial |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 0 | 0
2020 | 0 | 0
2019 | 0 | 0
2018 | 0 | 4,401
2017 | 0 | 0
2016 and Prior | 0 | 0
Revolving | 0 | 0
Revolving-Term | 0 | 0
Total | 0 | 4,401
Commercial | Doubtful | Commercial construction |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 0 | 0
2020 | 0 | 0
2019 | 0 | 0
2018 | 0 | 0
2017 | 0 | 0
2016 and Prior | 0 | 0
Revolving | 0 | 0
Revolving-Term | 0 | 0
Total | 0 | 0
Commercial | Doubtful | Business banking |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 0 | 0
2020 | 0 | 0
2019 | 0 | 0
2018 | 0 | 0
2017 | 0 | 0
2016 and Prior | 0 | 0
Revolving | 0 | 0
Revolving-Term | 0 | 0
Total | 0 | 0
Consumer |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 1,506,485 | 1,552,153
Consumer | Business banking |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 321,800 | 303,900
Consumer | Consumer real estate |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 20,000 | 120,736
2020 | 116,640 | 122,544
2019 | 111,128 | 69,931
2018 | 60,255 | 65,133
2017 | 56,942 | 76,254
2016 and Prior | 277,553 | 251,047
Revolving | 436,952 | 439,020
Revolving-Term | 24,630 | 22,667
Total | 1,104,099 | 1,167,332
Consumer | Other consumer |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 872 | 18,864
2020 | 14,119 | 13,162
2019 | 11,686 | 6,784
2018 | 5,848 | 3,395
2017 | 2,778 | 2,082
2016 and Prior | 7,255 | 4,054
Revolving | 35,525 | 27,391
Revolving-Term | 2,534 | 5,153
Total | 80,618 | 80,885
Consumer | Pass | Consumer real estate |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 20,000 | 120,736
2020 | 116,640 | 122,171
2019 | 110,942 | 67,700
2018 | 58,166 | 63,653
2017 | 55,435 | 73,805
2016 and Prior | 267,411 | 243,939
Revolving | 436,449 | 438,888
Revolving-Term | 23,550 | 22,667
Total | 1,088,594 | 1,153,559
Consumer | Pass | Other consumer |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 872 | 18,849
2020 | 14,119 | 13,162
2019 | 11,576 | 6,784
2018 | 5,723 | 3,395
2017 | 2,673 | 2,082
2016 and Prior | 2,283 | 687
Revolving | 35,151 | 26,647
Revolving-Term | 955 | 2,767
Total | 73,354 | 74,373
Consumer | Special mention | Consumer real estate |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 0 | 0
2020 | 0 | 0
2019 | 0 | 1,489
2018 | 0 | 0
2017 | 0 | 0
2016 and Prior | 2,246 | 150
Revolving | 0 | 132
Revolving-Term | 0 | 0
Total | 2,246 | 1,771
Consumer | Special mention | Other consumer |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 0 | 0
2020 | 0 | 0
2019 | 0 | 0
2018 | 0 | 0
2017 | 0 | 0
2016 and Prior | 0 | 0
Revolving | 0 | 0
Revolving-Term | 0 | 0
Total | 0 | 0
Consumer | Substandard | Consumer real estate |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 0 | 0
2020 | 0 | 373
2019 | 186 | 742
2018 | 2,089 | 1,480
2017 | 1,506 | 2,449
2016 and Prior | 7,896 | 6,958
Revolving | 503 | 0
Revolving-Term | 1,080 | 0
Total | 13,260 | 12,002
Consumer | Substandard | Other consumer |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 0 | 15
2020 | 0 | 0
2019 | 109 | 0
2018 | 125 | 0
2017 | 104 | 0
2016 and Prior | 4,968 | 3,367
Revolving | 374 | 744
Revolving-Term | 1,579 | 2,386
Total | 7,260 | 6,512
Consumer | Doubtful | Consumer real estate |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 0 | 0
2020 | 0 | 0
2019 | 0 | 0
2018 | 0 | 0
2017 | 0 | 0
2016 and Prior | 0 | 0
Revolving | 0 | 0
Revolving-Term | 0 | 0
Total | 0 | 0
Consumer | Doubtful | Other consumer |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
2021 | 0 | 0
2020 | 0 | 0
2019 | 0 | 0
2018 | 0 | 0
2017 | 0 | 0
2016 and Prior | 4 | 0
Revolving | 0 | 0
Revolving-Term | 0 | 0
Total | $ 4 | $ 0

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