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Variable Interest Entities - Additional Information (Details) - USD ($) | 12 Months Ended
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Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Certified Development Entities |  |  |
Variable Interest Entities |  |  |
Tax credit period | 7 years |  |
Variable Interest Entity, Not Primary Beneficiary |  |  |
Variable Interest Entities |  |  |
Tax credit period | 10 years |  |
Tax credit compliance period | 15 years |  |
Impairment losses | $ 0 | $ 0 | $ 0
Other assets | Variable Interest Entity, Not Primary Beneficiary |  |  |
Variable Interest Entities |  |  |
Carrying value of equity investments in LIHTCs | $ 45,953,000 | $ 41,521,000 |

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- Definition Amount of write-down from impairment of an investment in a qualified affordable housing project. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 740 -Section 50 -Paragraph 2 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=116633289&loc=SL49122993-202985 + Details
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