Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Tax Disclosure [Abstract]
Provision for income taxes	$ 96	$ 27
Effective income tax rate	0.78%	0.44%
Unrecognized tax benefits	$ 300
Unrecognized tax benefits that would favorably impact effective tax rate	$ 300