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Noncontrolling Interest - Additional Information (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2017 | Dec. 31, 2015
Variable Interest Entity, Primary Beneficiary [Member] |  |
Noncontrolling Interest [Line Items] |  |
Contribution to joint venture |  | $ 1,530
Additional contribution commitments to joint venture | $ 1,530 |
Hite [Member] |  |
Noncontrolling Interest [Line Items] |  |
Contribution to joint venture |  | $ 1,470
Ownership percentage |  | 49.00%
Additional contribution commitments to joint venture | $ 1,470 |
Hite [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |
Noncontrolling Interest [Line Items] |  |
Variable interest entity, ownership percentage |  | 51.00%

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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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- Definition The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity. + References No definition available. + Details
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- Definition The cash outflow associated with the investment in or advances to an entity in which the reporting entity shares control of the entity with another party or group. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3213-108585 + Details
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- Details
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- Details
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