Aggregate Allocation of the Purchase Price of Acquisitions to Intangible Assets (Detail) (USD $)	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Acquired Finite-Lived Intangible Assets [Line Items]
Developed technology	$ 97,500,000	$ 158,860,000	$ 141,000,000
Customer relationships	58,400,000	74,280,000	291,800,000
Tradename and trademark	1,200,000	12,620,000	13,770,000
Non-competition agreements			1,200,000
IPR&D			174,600,000
Other		3,379,000
Total intangible assets	$ 157,100,000	$ 249,139,000	$ 622,370,000