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Investments in Qualified Affordable Housing Projects Investments in Qualified Affordable Housing Projects - Narrative (Details) - USD ($) | 3 Months Ended |  |  |
--- | --- | --- | --- | ---
Mar. 31, 2017 | Sep. 30, 2017 | Jul. 01, 2017 | Dec. 31, 2016
Schedule of Equity Method Investments [Line Items] |  |  |  |
Carrying value of qualified affordable housing project investments |  | $ 8,359,000 |  | $ 6,331,000
Funding obligation related to qualified affordable housing projects | $ 2,450,000 |  |  |
Funding obligation related to qualified affordable housing projects | $ 0 |  |  |
Metropolitan Bancgroup, Inc. |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |
Carrying value of qualified affordable housing project investments |  |  | $ 5,469,000 |

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- Definition Amortization Method Qualified Affordable Housing Project Investments, Increase (Decrease) + References No definition available. + Details
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- Definition Amount of investment in qualified affordable housing projects. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 740 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=64813897&loc=SL49122993-202985 + Details
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- Definition Amount of commitment or contingent commitments to qualified affordable housing project investments. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 740 -Section 50 -Paragraph 2 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=64813897&loc=SL49122993-202985 + Details
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