Other Balance Sheet Amounts - Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 46,699	$ 40,669
Less: accumulated depreciation and amortization	(22,737)	(13,648)
Total property and equipment, net	23,962	27,021
Depreciation expense	$ 9,900	7,600	$ 5,200
Minimum
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	2 years
Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	7 years
Computer equipment and software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 32,926	26,870
Computer equipment and software | Minimum
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	3 years
Computer equipment and software | Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	5 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 3,837	3,648
Property and equipment, useful life	7 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 9,878	9,972
Leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	2 years
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	6 years
Renovation in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 58	$ 179