Property and Equipment, net (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Property and Equipment, net
Property and equipment, gross	$ 45,735	$ 27,092
Less: Accumulated depreciation	(17,047)	(11,854)
Total property and equipment, net	28,688	15,238
Lease financing obligation	5,970
Computer equipment and internally developed software
Property and Equipment, net
Property and equipment, gross	34,316	22,517
Furniture and Fixtures
Property and Equipment, net
Property and equipment, gross	2,110	1,654
Leasehold Improvements
Property and Equipment, net
Property and equipment, gross	3,339	2,921
Capitalized facility lease
Property and Equipment, net
Property and equipment, gross	5,970
Lease financing obligation	$ 6,000