Property, Equipment and Software, net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Property, equipment and software, at cost	$ 42,957	$ 24,191
Less accumulated depreciation and amortization	(16,770)	(10,262)
Property, equipment and software, net	26,187	13,929
Computer/office equipment
Property, Plant and Equipment [Line Items]
Property, equipment and software, at cost	$ 11,866	$ 7,249
Computer/office equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Life	12 months	12 months
Computer/office equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Life	36 months	36 months
Capitalized internal-use software
Property, Plant and Equipment [Line Items]
Estimated Useful Life	36 months	36 months
Property, equipment and software, at cost	$ 15,674	$ 10,599
Amortization expense	2,800	1,800	$ 1,200
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, equipment and software, at cost	$ 15,417	$ 6,343