Intangible Assets Gross Carrying Amount and Accumulated Amortization (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2011
Intangible Assets [Line Items]
Gross Assets	$ 781,916	$ 802,540	$ 765,712	$ 749,194
Accumulated Amortization	(560,769)	(563,769)
Net	221,147	238,771
Core-developed technology [Member]
Intangible Assets [Line Items]
Gross Assets	418,123	407,024
Accumulated Amortization	(331,603)	(332,763)
Net	86,520	74,261
Customer contracts and relationships [Member]
Intangible Assets [Line Items]
Gross Assets	281,697	292,252
Accumulated Amortization	(154,042)	(154,890)
Net	127,655	137,362
Trademarks and trade names [Member]
Intangible Assets [Line Items]
Gross Assets	71,004	72,770
Accumulated Amortization	(64,100)	(65,090)
Net	6,904	7,680
Other [Member]
Intangible Assets [Line Items]
Gross Assets	11,092	11,094
Accumulated Amortization	(11,024)	(11,026)
Net	68	68
In-process research and development
Intangible Assets [Line Items]
Indefinite-lived Intangible Assets	0	19,400
Intangible Asset Subject to Amortization [Member]
Intangible Assets [Line Items]
Gross Assets	781,916	783,140
Accumulated Amortization	(560,769)	(563,769)
Net	$ 221,147	$ 219,371