Amounts Recognized for Share-Based Compensation (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total cost of share-based compensation plans	$ 11,500,000	$ 11,100,000	$ 39,000,000	$ 36,500,000
Amounts capitalized in inventory and fixed assets	(400,000)	(300,000)	(1,200,000)	(1,000,000)
Amounts recognized in income for amounts previously capitalized in inventory and fixed assets	400,000	300,000	1,200,000	1,200,000
Amounts charged against income	$ 11,500,000	$ 11,100,000	$ 39,000,000	$ 36,700,000