Stock-Based Compensation Plans - Summary of Stock Option Award Activity (Detail) (Stock Options, USD $)	9 Months Ended
	Sep. 30, 2014
Stock Options
Number of Shares
Outstanding, beginning balance	5,147,837	[1]
Granted	446,310	[1]
Exercised	(696,159)	[1]
Forfeited, canceled or expired	(20,761)	[1]
Outstanding, ending balance	4,877,227	[1]
Weighted Average Exercise Price
Outstanding, beginning balance (in USD per share)	$ 40.08
Granted (in USD per share)	$ 85.02
Exercised (in USD per share)	$ 32.12
Forfeited, canceled or expired (in USD per share)	$ 49.67
Outstanding, ending balance (in USD per share)	$ 45.28

[1] Includes an immaterial number of stock appreciation rights.