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LOANS, Amount of Business Lending Loans by Credit Quality Category (Details) - USD ($) $ in Thousands | Mar. 31, 2019 | Dec. 31, 2018
--- | --- | ---
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | $ 6,266,086 | $ 6,281,121
Legacy Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 5,063,554 | 5,027,984
Acquired Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 1,202,532 | 1,253,137
Business Lending [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 2,410,477 | 2,396,977
Business Lending [Member] | Legacy Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 1,663,207 | 1,618,827
Business Lending [Member] | Acquired Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 747,270 | 778,150
Business Lending [Member] | Pass [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 2,134,790 | 2,141,830
Business Lending [Member] | Pass [Member] | Legacy Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 1,475,145 | 1,439,337
Business Lending [Member] | Pass [Member] | Acquired Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 659,645 | 702,493
Business Lending [Member] | Special Mention [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 161,691 | 145,172
Business Lending [Member] | Special Mention [Member] | Legacy Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 108,129 | 105,065
Business Lending [Member] | Special Mention [Member] | Acquired Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 53,562 | 40,107
Business Lending [Member] | Classified [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 108,654 | 102,950
Business Lending [Member] | Classified [Member] | Legacy Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 79,933 | 74,425
Business Lending [Member] | Classified [Member] | Acquired Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 28,721 | 28,525
Business Lending [Member] | Doubtful [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 0 | 1,579
Business Lending [Member] | Doubtful [Member] | Legacy Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 0 | 0
Business Lending [Member] | Doubtful [Member] | Acquired Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 0 | 1,579
Business Lending [Member] | Acquired Impaired [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 5,342 | 5,446
Business Lending [Member] | Acquired Impaired [Member] | Legacy Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 0 | 0
Business Lending [Member] | Acquired Impaired [Member] | Acquired Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 5,342 | 5,446
All Other Loans [Member] | Legacy Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 3,400,347 | 3,409,157
All Other Loans [Member] | Acquired Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 455,262 | 474,987
All Other Loans [Member] | Performing [Member] | Legacy Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 3,386,445 | 3,395,920
All Other Loans [Member] | Performing [Member] | Acquired Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 452,428 | 471,774
All Other Loans [Member] | Nonperforming [Member] | Legacy Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 13,902 | 13,237
All Other Loans [Member] | Nonperforming [Member] | Acquired Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 2,834 | 3,213
Consumer Mortgage [Member] | Legacy Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 1,864,445 | 1,848,450
Consumer Mortgage [Member] | Acquired Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 372,985 | 386,958
Consumer Mortgage [Member] | Performing [Member] | Legacy Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 1,852,691 | 1,837,185
Consumer Mortgage [Member] | Performing [Member] | Acquired Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 370,744 | 384,336
Consumer Mortgage [Member] | Nonperforming [Member] | Legacy Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 11,754 | 11,265
Consumer Mortgage [Member] | Nonperforming [Member] | Acquired Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 2,241 | 2,622
Consumer Indirect [Member] | Legacy Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 1,061,518 | 1,072,392
Consumer Indirect [Member] | Acquired Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 9,322 | 10,815
Consumer Indirect [Member] | Performing [Member] | Legacy Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 1,061,317 | 1,072,134
Consumer Indirect [Member] | Performing [Member] | Acquired Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 9,289 | 10,781
Consumer Indirect [Member] | Nonperforming [Member] | Legacy Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 201 | 258
Consumer Indirect [Member] | Nonperforming [Member] | Acquired Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 33 | 34
Consumer Direct [Member] | Legacy Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 170,360 | 175,774
Consumer Direct [Member] | Acquired Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 2,682 | 3,046
Consumer Direct [Member] | Performing [Member] | Legacy Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 170,319 | 175,726
Consumer Direct [Member] | Performing [Member] | Acquired Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 2,657 | 3,042
Consumer Direct [Member] | Nonperforming [Member] | Legacy Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 41 | 48
Consumer Direct [Member] | Nonperforming [Member] | Acquired Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 25 | 4
Home Equity [Member] | Legacy Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 304,024 | 312,541
Home Equity [Member] | Acquired Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 70,273 | 74,168
Home Equity [Member] | Performing [Member] | Legacy Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 302,118 | 310,875
Home Equity [Member] | Performing [Member] | Acquired Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 69,738 | 73,615
Home Equity [Member] | Nonperforming [Member] | Legacy Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | 1,906 | 1,666
Home Equity [Member] | Nonperforming [Member] | Acquired Loans [Member] |  |
Business Lending Loans by Credit Quality Category [Abstract] |  |
Loans | $ 535 | $ 553

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