XML 56 R46.htm IDEA: XBRL DOCUMENT
v3.21.2

Allowance for Credit Losses - Loan Balances by Year of Origination and Performing and Nonperforming Status (Details) - USD ($) $ in Thousands | Sep. 30, 2021 | Dec. 31, 2020
--- | --- | ---
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | $ 1,035,267 | $ 1,360,684
Year two | 854,925 | 1,214,746
Year three | 1,107,652 | 831,734
Year four | 688,325 | 565,201
Year five | 462,114 | 610,556
More than five years | 1,692,697 | 1,572,826
Revolving | 1,100,863 | 1,041,199
Revolving-Term | 28,244 | 28,914
Total | 6,970,087 | 7,225,860
Performing |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 1,030,025 | 1,360,654
Year two | 854,873 | 1,196,492
Year three | 1,065,779 | 827,626
Year four | 683,359 | 543,253
Year five | 450,806 | 586,622
More than five years | 1,649,520 | 1,496,134
Revolving | 1,097,042 | 1,040,545
Revolving-Term | 27,371 | 27,760
Total | 6,858,775 | 7,079,086
Nonperforming |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 5,242 | 30
Year two | 52 | 18,254
Year three | 41,873 | 4,108
Year four | 4,966 | 21,948
Year five | 11,308 | 23,934
More than five years | 43,177 | 76,692
Revolving | 3,821 | 654
Revolving-Term | 873 | 1,154
Total | 111,312 | 146,774
Pass |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 1,029,863 | 1,355,292
Year two | 847,760 | 1,136,716
Year three | 1,017,394 | 792,352
Year four | 653,430 | 502,350
Year five | 394,438 | 494,436
More than five years | 1,416,288 | 1,337,222
Revolving | 1,081,538 | 1,011,297
Revolving-Term | 24,651 | 25,724
Total | 6,465,362 | 6,655,389
Special mention |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 162 | 5,274
Year two | 4,448 | 47,302
Year three | 34,953 | 19,350
Year four | 8,994 | 24,802
Year five | 39,973 | 57,026
More than five years | 112,175 | 91,677
Revolving | 10,866 | 24,296
Revolving-Term | 121 | 124
Total | 211,692 | 269,851
Substandard |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 5,242 | 118
Year two | 2,717 | 30,083
Year three | 45,441 | 20,032
Year four | 25,901 | 33,648
Year five | 27,703 | 57,105
More than five years | 164,234 | 137,398
Revolving | 8,459 | 5,606
Revolving-Term | 3,472 | 3,066
Total | 283,169 | 287,056
Doubtful |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 0 | 0
Year two | 0 | 645
Year three | 9,864 | 0
Year four | 0 | 4,401
Year five | 0 | 1,989
More than five years | 0 | 6,529
Revolving | 0 | 0
Revolving-Term | 0 | 0
Total | 9,864 | 13,564
Commercial |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 5,423,964 | 5,673,707
Non - performing | 1,700 |
Commercial | 2010 |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Non - performing | 300 |
Commercial | 2012 |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Non - performing | 900 |
Commercial | 2013 |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Non - performing | 500 |
Commercial | Commercial real estate |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 255,876 | 334,086
Year two | 325,327 | 476,203
Year three | 493,611 | 417,944
Year four | 365,129 | 320,140
Year five | 281,897 | 415,184
More than five years | 937,114 | 780,560
Revolving | 43,826 | 47,830
Revolving-Term | 0 | 0
Total | 2,702,780 | 2,791,947
Commercial | Commercial real estate | Performing |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 255,876 | 334,086
Year two | 325,327 | 459,799
Year three | 477,766 | 417,944
Year four | 362,382 | 313,465
Year five | 275,458 | 394,972
More than five years | 907,348 | 722,781
Revolving | 43,826 | 47,830
Revolving-Term | 0 | 0
Total | 2,647,983 | 2,690,877
Commercial | Commercial real estate | Nonperforming |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 0 | 0
Year two | 0 | 16,404
Year three | 15,845 | 0
Year four | 2,747 | 6,675
Year five | 6,439 | 20,212
More than five years | 29,766 | 57,779
Revolving | 0 | 0
Revolving-Term | 0 | 0
Total | 54,797 | 101,070
Commercial | Commercial real estate | Pass |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 255,876 | 334,086
Year two | 323,514 | 422,800
Year three | 443,487 | 394,963
Year four | 341,387 | 277,724
Year five | 224,258 | 307,321
More than five years | 716,460 | 615,217
Revolving | 42,326 | 46,330
Revolving-Term | 0 | 0
Total | 2,347,308 | 2,398,441
Commercial | Commercial real estate | Special mention |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 0 | 0
Year two | 1,368 | 35,499
Year three | 32,780 | 10,200
Year four | 4,422 | 22,502
Year five | 38,966 | 55,174
More than five years | 97,322 | 75,022
Revolving | 0 | 0
Revolving-Term |  | 0
Total | 174,858 | 198,397
Commercial | Commercial real estate | Substandard |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 0 | 0
Year two | 445 | 17,259
Year three | 16,812 | 12,781
Year four | 19,320 | 19,914
Year five | 18,673 | 50,700
More than five years | 123,332 | 83,792
Revolving | 1,500 | 1,500
Revolving-Term |  | 0
Total | 180,082 | 185,946
Commercial | Commercial real estate | Doubtful |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 0 | 0
Year two | 0 | 645
Year three | 532 | 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 | 532 | 9,163
Commercial | Commercial and industrial |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 406,445 | 457,828
Year two | 159,516 | 215,457
Year three | 175,718 | 145,290
Year four | 102,677 | 82,249
Year five | 48,349 | 28,488
More than five years | 141,411 | 221,609
Revolving | 444,082 | 408,631
Revolving-Term |  | 0
Total | 1,478,198 | 1,559,552
Commercial | Commercial and industrial | Performing |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 401,249 | 457,828
Year two | 159,516 | 214,144
Year three | 153,731 | 143,706
Year four | 102,310 | 69,411
Year five | 44,963 | 28,426
More than five years | 141,201 | 220,701
Revolving | 441,319 | 408,351
Revolving-Term | 0 | 0
Total | 1,444,289 | 1,542,567
Commercial | Commercial and industrial | Nonperforming |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 5,196 | 0
Year two |  | 1,313
Year three | 21,987 | 1,584
Year four | 367 | 12,838
Year five | 3,386 | 62
More than five years | 210 | 908
Revolving | 2,763 | 280
Revolving-Term | 0 | 0
Total | 33,909 | 16,985
Commercial | Commercial and industrial | Pass |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 401,200 | 454,131
Year two | 156,589 | 199,453
Year three | 145,923 | 140,049
Year four | 98,137 | 68,607
Year five | 43,019 | 27,645
More than five years | 133,945 | 206,782
Revolving | 428,398 | 383,082
Revolving-Term | 0 | 0
Total | 1,407,211 | 1,479,749
Commercial | Commercial and industrial | Special mention |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 49 | 3,697
Year two | 2,927 | 8,211
Year three | 1,283 | 2,628
Year four | 3,166 | 697
Year five | 72 | 768
More than five years | 1,934 | 1,046
Revolving | 10,667 | 23,527
Revolving-Term |  | 0
Total | 20,098 | 40,574
Commercial | Commercial and industrial | Substandard |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 5,196 | 0
Year two | 0 | 7,793
Year three | 19,180 | 2,613
Year four | 1,374 | 8,544
Year five | 5,258 | 75
More than five years | 5,532 | 13,781
Revolving | 5,017 | 2,022
Revolving-Term |  | 0
Total | 41,557 | 34,828
Commercial | Commercial and industrial | Doubtful |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 0 | 0
Year two | 0 | 0
Year three | 9,332 | 0
Year four | 0 | 4,401
Year five | 0 | 0
More than five years | 0 | 0
Revolving | 0 | 0
Revolving-Term | 0 | 0
Total | 9,332 | 4,401
Commercial | Commercial construction |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 100,774 | 132,813
Year two | 136,589 | 230,907
Year three | 179,924 | 63,535
Year four | 33,903 | 2,921
Year five | 996 | 6,346
More than five years | 12,024 | 16,777
Revolving | 21,714 | 12,778
Revolving-Term |  | 0
Total | 485,924 | 466,077
Commercial | Commercial construction | Performing |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 100,774 | 132,813
Year two | 136,589 | 230,907
Year three | 176,567 | 63,535
Year four | 33,903 | 2,921
Year five | 996 | 6,346
More than five years | 11,328 | 16,393
Revolving | 21,714 | 12,778
Revolving-Term | 0 | 0
Total | 481,871 | 465,693
Commercial | Commercial construction | Nonperforming |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 0 | 0
Year two | 0 | 0
Year three | 3,357 | 0
Year four | 0 | 0
Year five | 0 | 0
More than five years | 696 | 384
Revolving | 0 | 0
Revolving-Term | 0 | 0
Total | 4,053 | 384
Commercial | Commercial construction | Pass |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 100,774 | 131,235
Year two | 134,440 | 224,794
Year three | 172,508 | 59,649
Year four | 33,903 | 2,420
Year five | 996 | 6,346
More than five years | 4,298 | 4,555
Revolving | 21,714 | 12,778
Revolving-Term | 0 | 0
Total | 468,633 | 441,777
Commercial | Commercial construction | Special mention |  |
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 | 4,491 | 8,593
Revolving | 0 | 0
Revolving-Term |  | 0
Total | 4,491 | 16,590
Commercial | Commercial construction | Substandard |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 0 | 0
Year two | 2,149 | 3,580
Year three | 7,416 | 0
Year four | 0 | 501
Year five | 0 | 0
More than five years | 3,235 | 3,629
Revolving | 0 | 0
Revolving-Term |  | 0
Total | 12,800 | 7,710
Commercial | Commercial construction | Doubtful |  |
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 | Business banking |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 173,313 | 296,357
Year two | 115,055 | 156,473
Year three | 155,033 | 128,250
Year four | 122,227 | 91,363
Year five | 84,905 | 82,202
More than five years | 344,047 | 298,779
Revolving | 104,339 | 105,549
Revolving-Term | 1,206 | 1,094
Total | 1,100,125 | 1,160,067
Commercial | Business banking | Performing |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 173,267 | 296,327
Year two | 115,055 | 156,164
Year three | 154,639 | 126,432
Year four | 120,811 | 90,414
Year five | 84,187 | 80,106
More than five years | 336,486 | 286,970
Revolving | 104,310 | 105,494
Revolving-Term | 1,149 | 1,037
Total | 1,089,904 | 1,142,944
Commercial | Business banking | Nonperforming |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 46 | 30
Year two | 0 | 309
Year three | 394 | 1,818
Year four | 1,416 | 949
Year five | 718 | 2,096
More than five years | 7,561 | 11,809
Revolving | 29 | 55
Revolving-Term | 57 | 57
Total | 10,221 | 17,123
Commercial | Business banking | Pass |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 173,154 | 296,254
Year two | 114,831 | 154,335
Year three | 152,423 | 123,207
Year four | 117,529 | 86,552
Year five | 81,934 | 77,238
More than five years | 316,445 | 266,042
Revolving | 103,162 | 103,571
Revolving-Term | 450 | 291
Total | 1,059,928 | 1,107,490
Commercial | Business banking | Special mention |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 113 | 0
Year two | 153 | 1,060
Year three | 890 | 1,147
Year four | 1,406 | 1,602
Year five | 935 | 1,084
More than five years | 6,265 | 6,866
Revolving | 199 | 637
Revolving-Term | 121 | 123
Total | 10,082 | 12,519
Commercial | Business banking | Substandard |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 46 | 103
Year two | 71 | 1,078
Year three | 1,720 | 3,896
Year four | 3,292 | 3,209
Year five | 2,036 | 3,880
More than five years | 21,337 | 25,871
Revolving | 978 | 1,341
Revolving-Term | 635 | 680
Total | 30,115 | 40,058
Commercial | Business banking | Doubtful |  |
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 |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 1,546,123 | 1,552,153
Consumer | Business banking |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total |  | 303,900
Consumer | Consumer real estate |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 89,026 | 120,736
Year two | 107,534 | 122,544
Year three | 94,791 | 69,931
Year four | 60,387 | 65,133
Year five | 44,157 | 76,254
More than five years | 249,283 | 251,047
Revolving | 435,922 | 439,020
Revolving-Term | 24,378 | 22,667
Total | 1,105,478 | 1,167,332
Consumer | Consumer real estate | Performing |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 89,026 | 120,736
Year two | 107,482 | 122,315
Year three | 94,501 | 69,225
Year four | 60,140 | 63,647
Year five | 43,392 | 74,690
More than five years | 244,339 | 245,331
Revolving | 434,893 | 438,701
Revolving-Term | 23,562 | 21,571
Total | 1,097,335 | 1,156,216
Consumer | Consumer real estate | Nonperforming |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 0 | 0
Year two | 52 | 229
Year three | 290 | 706
Year four | 247 | 1,486
Year five | 765 | 1,564
More than five years | 4,944 | 5,716
Revolving | 1,029 | 319
Revolving-Term | 816 | 1,096
Total | 8,143 | 11,116
Consumer | Consumer real estate | Pass |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 89,026 | 120,736
Year two | 107,534 | 122,171
Year three | 94,583 | 67,700
Year four | 58,622 | 63,653
Year five | 42,789 | 73,805
More than five years | 242,252 | 243,939
Revolving | 435,213 | 438,888
Revolving-Term | 23,088 | 22,667
Total | 1,093,107 | 1,153,559
Consumer | Consumer real estate | Special mention |  |
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 | 2,163 | 150
Revolving | 0 | 132
Revolving-Term |  | 0
Total | 2,163 | 1,771
Consumer | Consumer real estate | Substandard |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 0 | 0
Year two | 0 | 373
Year three | 208 | 742
Year four | 1,765 | 1,480
Year five | 1,368 | 2,449
More than five years | 4,868 | 6,958
Revolving | 709 | 0
Revolving-Term | 1,290 | 0
Total | 10,208 | 12,002
Consumer | Consumer real estate | Doubtful |  |
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 | Other consumer |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 9,833 | 18,864
Year two | 10,904 | 13,162
Year three | 8,575 | 6,784
Year four | 4,002 | 3,395
Year five | 1,810 | 2,082
More than five years | 8,818 | 4,054
Revolving | 50,980 | 27,391
Revolving-Term | 2,660 | 5,153
Total | 97,582 | 80,885
Consumer | Other consumer | Performing |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 9,833 | 18,864
Year two | 10,904 | 13,162
Year three | 8,575 | 6,784
Year four | 3,813 | 3,395
Year five | 1,810 | 2,082
More than five years | 8,818 | 3,958
Revolving | 50,980 | 27,391
Revolving-Term | 2,660 | 5,153
Total | 97,393 | 80,789
Consumer | Other consumer | Nonperforming |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 0 | 0
Year two | 0 | 0
Year three | 0 | 0
Year four | 189 | 0
Year five | 0 | 0
More than five years | 0 | 96
Revolving | 0 | 0
Revolving-Term | 0 | 0
Total | 189 | 96
Consumer | Other consumer | Pass |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 9,833 | 18,849
Year two | 10,852 | 13,162
Year three | 8,470 | 6,784
Year four | 3,852 | 3,395
Year five | 1,442 | 2,082
More than five years | 2,888 | 687
Revolving | 50,725 | 26,647
Revolving-Term | 1,113 | 2,767
Total | 89,175 | 74,373
Consumer | Other consumer | Special mention |  |
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 | Other consumer | Substandard |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Current fiscal year | 0 | 15
Year two | 52 | 0
Year three | 105 | 0
Year four | 150 | 0
Year five | 368 | 0
More than five years | 5,930 | 3,367
Revolving | 255 | 744
Revolving-Term | 1,547 | 2,386
Total | 8,407 | 6,512
Consumer | Other consumer | Doubtful |  |
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

X
- Definition Amount excluding accrued interest, before allowance for credit loss, of financing receivable. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 5 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=124255953&loc=SL82919230-210447 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 3B -URI http://asc.fasb.org/extlink&oid=124255953&loc=SL120267963-210447 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount excluding accrued interest of financing receivable originated more than five years prior to current fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 3B -URI http://asc.fasb.org/extlink&oid=124255953&loc=SL120267963-210447 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=124255953&loc=SL82919232-210447 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI http://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount excluding accrued interest of financing receivable that can be withdrawn, repaid, and redrawn. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=124255953&loc=SL82919232-210447 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI http://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 3B -URI http://asc.fasb.org/extlink&oid=124255953&loc=SL120267963-210447 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestRevolving
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount excluding accrued interest of revolving financing receivable converted to term loan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 3B -URI http://asc.fasb.org/extlink&oid=124255953&loc=SL120267963-210447 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI http://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6A -URI http://asc.fasb.org/extlink&oid=124255953&loc=SL120270059-210447 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestRevolvingConvertedToTermLoan
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount excluding accrued interest of financing receivable originated four years prior to current fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI http://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=124255953&loc=SL82919232-210447 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 3B -URI http://asc.fasb.org/extlink&oid=124255953&loc=SL120267963-210447 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount excluding accrued interest of financing receivable originated three years prior to current fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=124255953&loc=SL82919232-210447 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI http://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 3B -URI http://asc.fasb.org/extlink&oid=124255953&loc=SL120267963-210447 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount excluding accrued interest of financing receivable originated in current fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=124255953&loc=SL82919232-210447 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI http://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 3B -URI http://asc.fasb.org/extlink&oid=124255953&loc=SL120267963-210447 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount excluding accrued interest of financing receivable originated two years prior to current fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 3B -URI http://asc.fasb.org/extlink&oid=124255953&loc=SL120267963-210447 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=124255953&loc=SL82919232-210447 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI http://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount excluding accrued interest of financing receivable originated in fiscal year prior to current fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 3B -URI http://asc.fasb.org/extlink&oid=124255953&loc=SL120267963-210447 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=124255953&loc=SL82919232-210447 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI http://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, before valuation allowance, of financing receivable classified as held-for-sale. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=124259787&loc=d3e4428-111522 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 948 -SubTopic 310 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=124265262&loc=d3e48678-111004 + Details
Name: | us-gaap_LoansReceivableHeldForSaleAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FinancialInstrumentPerformanceStatusAxis=us-gaap_PerformingFinancingReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentPerformanceStatusAxis=us-gaap_NonperformingFinancingReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=us-gaap_PassMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=us-gaap_SpecialMentionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=us-gaap_SubstandardMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=us-gaap_DoubtfulMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | stba_FinancingReceivableOriginationYearAxis=stba_A2010Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | stba_FinancingReceivableOriginationYearAxis=stba_A2012Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | stba_FinancingReceivableOriginationYearAxis=stba_A2013Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialRealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=stba_CommercialAndIndustrialMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConstructionLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=stba_BusinessBankingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=stba_ConsumerRealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=stba_OtherConsumerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |