Goodwill and Acquired Intangible Assets Schedule of Other Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 192,571	$ 195,191
Accumulated amortization	(115,142)	(110,637)
Net carrying amount	77,429	84,554
Completed technologies
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	65,631	71,531
Accumulated amortization	(35,476)	(32,842)
Net carrying amount	30,155	38,689
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	115,100	104,700
Accumulated amortization	(75,563)	(68,702)
Net carrying amount	39,537	35,998
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	7,950	14,770
Accumulated amortization	(2,623)	(7,645)
Net carrying amount	5,327	7,125
Trademarks and trade names
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	3,400	3,700
Accumulated amortization	(990)	(958)
Net carrying amount	2,410	2,742
Acquired license rights
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	490	490
Accumulated amortization	(490)	(490)
Net carrying amount	$ 0	$ 0