Changes in Options Outstanding (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Number of Shares
Exercised	(482,974)	[1]	(615,674)	[1]	(1,495,926)	[1]
Outstanding at end of year	5,907,359
Exercisable at end of year	2,474,636
Stock Options
Number of Shares
Outstanding at beginning of year	5,434,228		5,302,384		5,431,560
Granted at FMV	1,870,500		1,397,312		1,605,628
Exercised	(823,855)		(974,500)		(1,580,950)
Forfeited	(573,514)		(290,968)		(153,854)
Outstanding at end of year	5,907,359		5,434,228		5,302,384
Exercisable at end of year	2,474,636		2,319,735		2,499,610		3,506,310
Average Exercise Price
Outstanding at beginning of year	$ 55.17		$ 48.83		$ 42.01
Granted at FMV	$ 57.96		$ 67.64		$ 52.85
Exercised	$ 38.37		$ 39.30		$ 29.04
Forfeited	$ 60.43		$ 52.73		$ 53.33
Outstanding at end of year	$ 57.89		$ 55.17		$ 48.83
Exercisable at end of year	$ 54.43		$ 51.14		$ 45.07		$ 34.86

[1] Shares issued upon exercise of stock options are less than the amount reflected in Note I due to withholdings for statutory income taxes owed upon exercise.