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BORROWED FUNDS - Narrative (Details) - USD ($) | 1 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Sep. 30, 2012 | Dec. 31, 2016 | Dec. 31, 2015
Borrowings and junior subordinated debentures |  |  |
Line of credit |  | $ 3,000,000 |
Short-term borrowings |  | 1,082,044,000 | $ 1,071,200,000
Long-term borrowings |  | 231,953,000 | 192,118,000
Variable-rate FHLB advances |  | 0 |
Advances from the FHLBB |  |  |
Borrowings and junior subordinated debentures |  |  |
Outstanding balance, line of credit |  | 0 | 0
Short-term borrowings |  | 1,072,044,000 | 1,071,200,000
Long-term borrowings |  | 142,792,000 | 103,135,000
Federal Reserve Bank Advances |  |  |
Borrowings and junior subordinated debentures |  |  |
Short-term borrowings |  | 0 | 0
Federal Home Loan Bank Certificates And Obligations F H L B Callable Advances |  |  |
Borrowings and junior subordinated debentures |  |  |
Long-term borrowings |  | 11,000,000 | 11,000,000
Federal Home Loan Bank Certificates And Obligations F H L B Amortizing Advances |  |  |
Borrowings and junior subordinated debentures |  |  |
Long-term borrowings |  | 1,200,000 | 1,200,000
Subordinated notes |  |  |
Borrowings and junior subordinated debentures |  |  |
Long-term borrowings |  | 73,697,000 | 73,519,000
Maturity period | 15 years |  |
Principal amount of debt issued | $ 75,000,000.0 |  |
Discount rate (percent) | 1.15% |  |
Fixed interest rate (percent) | 6.875% |  |
Maturity period with fixed interest rate | 10 years |  |
Subordinated notes | Three-month LIBOR rate |  |  |
Borrowings and junior subordinated debentures |  |  |
Interest rate margin (percent) | 5.113% |  |
Unamortized debt issuance costs |  | 706,000 | 829,000
Junior subordinated notes |  |  |
Borrowings and junior subordinated debentures |  |  |
Long-term borrowings |  | $ 15,464,000 | $ 15,464,000
Junior subordinated notes | Trust I |  |  |
Borrowings and junior subordinated debentures |  |  |
Common stock of trust (percent) |  | 100.00% |
Common stock of trust included in other asset |  | $ 500,000 |
Sole asset of trust in form of debt |  | $ 15,500,000 |
Variable interest rate (percent) |  | 2.77% | 2.23%
Period up to which interest payments can be deferred |  | 5 years |
Junior subordinated notes | LIBOR | Trust I |  |  |
Borrowings and junior subordinated debentures |  |  |
Interest rate margin (percent) |  | 1.85% |

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- Definition Including the current and noncurrent portions, the carrying value of junior subordinated long-term debt owed to unconsolidated subsidiary trusts as of the balance sheet date. Such debt places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets and was initially scheduled to be repaid after one year or beyond the normal operating cycle if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.16) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 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 210.9-03.16) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
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- Definition The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(16)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 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(16)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
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- Definition The carrying value as of the balance sheet date of the current portion of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement. + References Reference 1: 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(13)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Line-of-Credit Arrangement -URI http://asc.fasb.org/extlink&oid=6517033 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(19)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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