Restructuring - Additional Information (Detail) (USD $)	3 Months Ended					6 Months Ended				12 Months Ended		30 Months Ended
	Jun. 30, 2012		Mar. 31, 2012	Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011		Dec. 31, 2011	Dec. 31, 2010	Jun. 30, 2012
Restructuring Cost and Reserve [Line Items]
Restructuring charges (credits)	$ (70,000)	[1]	$ 14,400,000	$ 2,983,000	[1]	$ 14,345,000	[1]	$ 3,963,000	[1]	$ 8,584,000	$ 2,196,000	$ 25,125,000
Restructuring charges	$ 1,000,000

[1] See Note 3 "Restructuring."