Components of Income Before Income Taxes (Detail) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Schedule of Income Before Income Tax [Line Items]
United States									$ 435,100,000	$ 425,100,000	$ 455,800,000
Foreign									297,300,000	85,700,000	261,900,000
Income from operations before income taxes	$ 177,300,000	$ 178,200,000	$ 185,500,000	$ 191,400,000	$ 142,000,000	$ 182,100,000	$ 2,700,000	$ 184,000,000	$ 732,400,000	$ 510,800,000	$ 717,700,000