Basis of Presentation, Summary of Significant Accounting Policies and Change in Accounting Principle - Revenue Recognition (Details) - Accounting Standards Update 2014-09 $ in Thousands	Jan. 01, 2018 USD ($)
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cumulative-effect adjustment from adoption of ASC 606	$ 17,309
Retained Earnings (Accumulated Deficit)
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cumulative-effect adjustment from adoption of ASC 606	$ 16,715

Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption.

No definition available.

Name:	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant