Commitments and Contingencies - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	2 Months Ended	12 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition, Contingent Consideration [Line Items]
Net rent expense			$ 1,200	$ 1,208	$ 783
Total settlement amount		$ 330
Insurance reimbursement	$ 174
Selling, general, and administrative | Settled litigation
Business Acquisition, Contingent Consideration [Line Items]
Insurance reimbursement					174
Litigation expense					$ (156)