Goodwill and Intangible Assets - Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross	$ 124,786	$ 121,693
Accumulated Amortization	(111,150)	(110,716)
Foreign Currency Translation	114	584
Intangible assets, net	13,750	11,561
Completed technology [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross	84,579	82,084
Accumulated Amortization	(77,391)	(77,243)
Foreign Currency Translation	(8)	254
Intangible assets, net	7,180	5,095
Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross	14,571	14,571
Accumulated Amortization	(9,125)	(8,886)
Foreign Currency Translation	109	312
Intangible assets, net	5,555	5,997
Patents, trademarks, trade names and other [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross	25,636	25,038
Accumulated Amortization	(24,634)	(24,587)
Foreign Currency Translation	13	18
Intangible assets, net	$ 1,015	$ 469