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Variable Interest Entities (Summary of the Impact of Qualifying LIHTC Investments) (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017
Low income housing tax credits |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |
Amortization of qualifying LIHTC investments | $ 2,191 | $ 2,362 | $ 4,547 | $ 4,640
Other tax benefits related to qualifying LIHTC investments | (2,560) | (2,598) | (5,097) | (4,998)
Other tax benefits related to qualifying LIHTC investments |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |
Other tax benefits related to qualifying LIHTC investments | $ (894) | $ (910) | $ (1,584) | $ (1,829)

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- Definition Amount of affordable housing tax credits and other tax benefits recognized. + 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 (a) -URI http://asc.fasb.org/extlink&oid=64813897&loc=SL49122993-202985 + Details
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- Definition Amount of amortization expense 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 (c) -URI http://asc.fasb.org/extlink&oid=64813897&loc=SL49122993-202985 + Details
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- 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
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