Summary of Significant Accounting Policies - Stock-Based Compensation (Details) - Accounting Standards Update 2016-09 $ in Thousands	Jan. 01, 2018 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of change in accounting treatment	$ 0
Accumulated Deficit
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of change in accounting treatment	$ (13)

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.

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