Balance Sheet Components - Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Property Plant And Equipment [Line Items]
Property and equipment, Total	$ 61,340	$ 52,154
Accumulated depreciation and amortization	(37,721)	(28,783)
Projects in process	2,832	2,028
Property and equipment, net	26,451	25,399
Software
Property Plant And Equipment [Line Items]
Property and equipment, Total	32,320	30,791
Computer Equipment
Property Plant And Equipment [Line Items]
Property and equipment, Total	21,368	17,325
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, Total	5,908	2,393
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property and equipment, Total	$ 1,744	$ 1,645