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Related Party Transactions - Additional Information (Detail) - Directors and Executive Officers [Member] $ in Thousands | 12 Months Ended
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Dec. 31, 2018 USD ($) SecurityLoan | Dec. 31, 2017 USD ($)
Related Party Transaction [Line Items] |  |
Granted loans to affiliate companies | $ 1,500 | $ 1,500
Subsequent advances | 9,400 |
Payment received | 9,500 |
Difference in related borrowings amounts | 45 |
Ownership interest amount | $ 26,100 | $ 23,400
Number of new loans approved | SecurityLoan | 2 |

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- Definition Number of new loans approved. + References No definition available. + Details
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- Definition The cash outflow associated with extending a long-term loan to a related party. Alternate caption: Payments for Advances to Affiliates. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3213-108585 + Details
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