Stock-Based Compensation Plans - Additional Information 2 (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 14,137,000	$ 12,286,000
Equity Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	6,500,000	4,300,000
Shares granted to employees	351,000	386,000
Restricted stock granted average price	$ 84.89	$ 71.02
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	4,700,000	4,500,000
Restricted stock granted average price	$ 85.02	$ 71.40
Vesting period of shares granted to employees	three-year	three-year
Shares granted to employees and directors	76,000	125,000
Liability Awards | Director
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock granted average price	$ 81.74
Shares granted to employees and directors	950
Performance Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 533,000	$ 533,000