Significant Accounting Policies - Recent Accounting Pronouncements (Details) - Accounting Standards Update 2014-09 $ in Millions	12 Months Ended
Dec. 31, 2017 USD ($)
New Accounting Pronouncements or Change in Accounting Principle
Capitalized costs	$ 6.2
Capitalized costs amortization period	5 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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