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Basis of Presentation - Additional Information (Detail) - USD ($) $ in Thousands | 3 Months Ended
--- | ---
Mar. 31, 2019 | Mar. 31, 2018
New Accounting Pronouncements Or Change In Accounting Principle [Line Items] |  |
Percentage of comparable consolidated amounts | 95.00% | 95.00%
Right-of-use assets | $ 539 |
Operating lease liabilities | 539 |
ASU 2016-02 [Member] |  |
New Accounting Pronouncements Or Change In Accounting Principle [Line Items] |  |
Right-of-use assets | 400 |
Operating lease liabilities | $ 300 |

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- Definition Present value of lessee's discounted obligation for lease payments from operating lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 45 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=77888419&loc=SL77918627-209977 + Details
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