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Concentration of Risk, Segment and Geographic Information - Additional Information 1 (Details) - Customer Concentration Risk [Member] - Partner | 12 Months Ended
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Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Revenues [Member] |  |  |
Concentration Risk [Line Items] |  |  |
Number of major partners | 1 | 3 | 1
Revenues [Member] | Partner 1 [Member] |  |  |
Concentration Risk [Line Items] |  |  |
Concentration risk, percentage (in hundredths) | 95.00% | 27.00% | 67.00%
Revenues [Member] | Partner 2 [Member] |  |  |
Concentration Risk [Line Items] |  |  |
Concentration risk, percentage (in hundredths) |  | 22.00% |
Revenues [Member] | Partner 3 [Member] |  |  |
Concentration Risk [Line Items] |  |  |
Concentration risk, percentage (in hundredths) |  | 19.00% |
Accounts Receivable [Member] |  |  |
Concentration Risk [Line Items] |  |  |
Number of major partners | 1 | 1 |
Accounts Receivable [Member] | Partner 1 [Member] |  |  |
Concentration Risk [Line Items] |  |  |
Concentration risk, percentage (in hundredths) | 100.00% | 85.00% |

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- Definition For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 18 -URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6351-108592 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13531-108611 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6404-108592 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 21 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13537-108611 + Details
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- Definition Number of external partners that accounts for 10 percent or more of an entity's revenues during the period. + References No definition available. + Details
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