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Other Real Estate Owned (OREO) - Additional Information (Detail) - USD ($) | 3 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Mar. 31, 2018 | Mar. 31, 2017 | Dec. 31, 2017 | Dec. 31, 2016
Other Real Estate [Line Items] |  |  |  |
Residential real estate carrying amount included in OREO | $ 0 |  | $ 326,000 | $ 250,000
Net expenses applicable to other real estate owned | 1,000 | $ 2,000 | 5,000 |
Residential real estate properties |  |  |  |
Other Real Estate [Line Items] |  |  |  |
Residential real estate carrying amount included in OREO | 0 |  | $ 0 |
Mortgage loans foreclosed | $ 0 |  |  |

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- Definition Other Real Estate [Line Items] + References No definition available. + Details
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- Definition Other real estate owned expenses. + References No definition available. + Details
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- Definition The amount of mortgage loans on real estate which were foreclosed on during the reporting period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 948 -SubTopic 310 -Section S99 -Paragraph 1 -Subparagraph (SX 210.12-29.6) -URI http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 10 -Section S99 -Paragraph 6 -Subparagraph (SX 210.5-04.(c) Schedule IV) -URI http://asc.fasb.org/extlink&oid=27047687&loc=d3e5864-122674 + Details
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- Definition Carrying amount of other real estate not separately disclosed, including, but not limited to, real estate investments, real estate loans that qualify as investments in real estate, and premises that are no longer used in operations may also be included in real estate owned. This does not include real estate assets taken in settlement of troubled loans through surrender or foreclosure. + 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 210.9-03.10(4)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
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