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Allowance for Loan Losses and Credit Quality of Loans, Allowance for Loan Losses by Portfolio Segments (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016
Changes in allowance for loan losses by portfolio segment [Roll Forward] |  |  |  |
Balance, beginning of period | $ 66,600 | $ 64,568 | $ 65,200 | $ 63,018
Charge-offs | (7,974) | (6,825) | (24,450) | (19,251)
Recoveries | 1,835 | 1,537 | 4,765 | 4,635
Provision | 7,889 | 6,388 | 22,835 | 17,266
Balance, end of period | 68,350 | 65,668 | 68,350 | 65,668
Allowance for loan losses for acquired loan portfolio | 0 | 700 | 0 | 700
Provision expense and net charge-offs related to acquired loans | 0 | 100 | 700 | 400
Commercial Loans [Member] |  |  |  |
Changes in allowance for loan losses by portfolio segment [Roll Forward] |  |  |  |
Balance, beginning of period | 24,428 | 25,222 | 25,444 | 25,545
Charge-offs | (574) | (637) | (2,991) | (1,723)
Recoveries | 266 | 512 | 919 | 1,616
Provision | 1,434 | 1,514 | 2,182 | 1,173
Balance, end of period | 25,554 | 26,611 | 25,554 | 26,611
Consumer Loans [Member] |  |  |  |
Changes in allowance for loan losses by portfolio segment [Roll Forward] |  |  |  |
Balance, beginning of period | 35,523 | 31,471 | 33,375 | 29,253
Charge-offs | (6,979) | (6,046) | (19,742) | (16,409)
Recoveries | 1,446 | 898 | 3,680 | 2,779
Provision | 6,197 | 6,078 | 18,874 | 16,778
Balance, end of period | 36,187 | 32,401 | 36,187 | 32,401
Residential Real Estate Mortgages [Member] |  |  |  |
Changes in allowance for loan losses by portfolio segment [Roll Forward] |  |  |  |
Balance, beginning of period | 6,649 | 7,875 | 6,381 | 7,960
Charge-offs | (421) | (142) | (1,717) | (1,119)
Recoveries | 123 | 127 | 166 | 240
Provision | 258 | (1,481) | 1,779 | (702)
Balance, end of period | 6,609 | 6,379 | 6,609 | 6,379
Unallocated [Member] |  |  |  |
Changes in allowance for loan losses by portfolio segment [Roll Forward] |  |  |  |
Balance, beginning of period | 0 | 0 | 0 | 260
Charge-offs | 0 | 0 | 0 | 0
Recoveries | 0 | 0 | 0 | 0
Provision | 0 | 277 | 0 | 17
Balance, end of period | $ 0 | $ 277 | $ 0 | $ 277

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- Definition Reduction to the allowance for credit losses related to acquired financing receivables deemed uncollectible and the sum of the periodic provision charged to earnings, based on an assessment of uncollectibility from the counterparty on account of acquired loan, lease or other credit losses, to reduce these accounts to the amount that approximates their net realizable value. + References No definition available. + Details
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- Definition Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(4) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524 + Details
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- Definition Amount of addition to allowance reserve for credit loss arising from purchase of loan and lease portfolios. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.7(d)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
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- Definition Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(3) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.7(d)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
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- Definition Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.7(d)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SAB Topic 6.L.1) -URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74567-122707 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (b)(1)(ii) -URI http://asc.fasb.org/extlink&oid=82894903&loc=d3e15032-111544 + Details
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- Definition Amount of expense related to estimated loss from loan and lease transactions. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.11) -URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524 + Details
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