Stock-Based Compensation Plans - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 Plans	Sep. 30, 2012	Dec. 31, 2012
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period			3 years
Expiration term of stock options			5 years
Active equity-based stock plans			2
Stock-based compensation expense	$ 13,244,000	$ 12,233,000	$ 40,979,000	$ 36,763,000
Non-cash, Mark-to-market income (loss) related to deferred compensation plan	2,200,000	(20,100,000)	(33,300,000)	(21,600,000)
Shares held in rabbi trust total	2,900,000		2,900,000		2,700,000
Vested shares held in rabbi trust	2,300,000		2,300,000		2,300,000
Equity Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares granted to employees			394,100	359,700
Granted			$ 71.13	$ 63.37
Stock-based compensation expense			14,600,000	8,200,000
Vesting period of shares granted to employees			three-year	three-year
Liability Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense			$ 16,000,000	$ 15,200,000
Vesting period of shares granted to employees			three-year	three-year
Liability Awards | Employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted			$ 75.45	$ 63.88
Shares granted			406,300	365,000
Liability Awards | Director
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted			$ 77.26	$ 64.35
Shares granted			18,300	14,700
Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of stock option outstanding	2,600,000		2,600,000