Property and Equipment, Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 42,476		$ 36,415
Accumulated depreciation and amortization	(7,017)		(5,236)
Total property and equipment, net	35,459		31,179
Depreciation expense	1,800	$ 700
Capitalized computer software, amortization	700	200
Computer hardware
Property, Plant and Equipment [Line Items]
Total property and equipment	4,674		4,474
Furniture and equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	2,448		2,448
Internal-use software development costs
Property, Plant and Equipment [Line Items]
Total property and equipment	27,237		21,385
Total property and equipment, net	25,000		19,900
Capitalized computer software additions	5,800	$ 3,400
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 8,117		$ 8,108