Summary of Significant Accounting Policies - Intangible assets and other Long-lived assets (Details)	12 Months Ended
Dec. 31, 2017
Minimum
Intangible assets
Estimated useful life of intangible assets	3 years
Maximum
Intangible assets
Estimated useful life of intangible assets	10 years

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.

No definition available.

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