Commitments and Contingencies - Additional Information (Details) $ in Millions	3 Months Ended
Mar. 31, 2018 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Increase in litigation accrual	$ 0.4
Litigation accrual	$ 0.6

Amount of increase (decrease) in loss contingency liability.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14326-108349

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration