Balance Sheet Components (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash and cash equivalents
Cash	$ 14,085	$ 8,598
Cash equivalents:
Money market funds	93,108	104,021
Certificates of deposit	25	25
Total cash equivalents	93,133	104,046
Cash and cash equivalents	107,218	112,644	$ 128,299	$ 44,247
Property and equipment, net
Total property and equipment	44,537	29,740
Less accumulated depreciation	(23,214)	(12,908)
Property and equipment, net	21,323	16,832
Depreciation expense	10,400	7,200	$ 3,900
Computer equipment
Property and equipment, net
Total property and equipment	28,159	18,384
Software
Property and equipment, net
Total property and equipment	3,498	2,417
Office furniture
Property and equipment, net
Total property and equipment	2,952	2,071
Leasehold improvements
Property and equipment, net
Total property and equipment	7,120	5,123
Construction in progress
Property and equipment, net
Total property and equipment	$ 2,808	$ 1,745