Goodwill and Acquired Intangible Assets - Schedule of Acquired Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 279,611	$ 192,571
Accumulated Amortization	(138,796)	(115,142)
Net Carrying Amount	140,815	77,429
Completed technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	92,431	65,631
Accumulated Amortization	(45,969)	(35,476)
Net Carrying Amount	46,462	30,155
Customer-related intangible assets
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	173,600	115,100
Accumulated Amortization	(87,009)	(75,563)
Net Carrying Amount	86,591	39,537
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	8,890	7,950
Accumulated Amortization	(3,804)	(2,623)
Net Carrying Amount	5,086	5,327
Trademarks and trade names
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	4,200	3,400
Accumulated Amortization	(1,524)	(990)
Net Carrying Amount	2,676	2,410
Acquired license rights
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	490	490
Accumulated Amortization	(490)	(490)
Net Carrying Amount	$ 0	$ 0