Intangible Assets Gross Carrying Amount and Accumulated Amortization (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012
Intangible Assets [Line Items]
Gross Assets	$ 802,208	$ 804,281	$ 781,916	$ 802,540
Accumulated Amortization	(618,156)	(608,441)
Net	184,052	195,840
Core-developed technology [Member]
Intangible Assets [Line Items]
Gross Assets	427,981	428,890
Accumulated Amortization	(361,601)	(356,017)
Net	66,380	72,873
Customer contracts and relationships [Member]
Intangible Assets [Line Items]
Gross Assets	290,198	291,185
Accumulated Amortization	(177,737)	(173,952)
Net	112,461	117,233
Trademarks and trade names [Member]
Intangible Assets [Line Items]
Gross Assets	72,942	73,117
Accumulated Amortization	(67,795)	(67,449)
Net	5,147	5,668
Other [Member]
Intangible Assets [Line Items]
Gross Assets	11,087	11,089
Accumulated Amortization	(11,023)	(11,023)
Net	$ 64	$ 66