Property and Equipment - Additional Disclosures (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Property, Plant and Equipment [Abstract]
Depreciation expense, inclusive of expense captured in cost of revenue	$ 2,400,000	$ 2,100,000	$ 7,000,000	$ 5,300,000
Impairment of property and equipment	$ 0	$ 0	$ 0	$ 0