Summary of Significant Accounting Policies - Goodwill and Intangible Assets (Details) - Intangible Assets	12 Months Ended
Dec. 31, 2017
Minimum
Intangible Assets
Amortized useful life (in years)	1 year
Maximum
Intangible Assets
Amortized useful life (in years)	16 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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Period Type:	duration