Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Tax Disclosure [Abstract]
(Provision for) benefit from income taxes	$ (189)	$ 13	$ (285)	$ (14)
Effective income tax rate	1.13%	(0.38%)	0.98%	0.15%
Unrecognized tax benefits	$ 400		$ 400
Unrecognized tax benefits that would favorably impact effective tax rate	$ 400		$ 400