Stock Option Activity (Detail) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012 Year
Options Outstanding - Number of Shares
Balance at December 31, 2011	9,807,252
Exercised	(517,067)
Forfeited/canceled	(37,679)
Balance at March 31, 2012	9,252,506
Vested and exercisable as of March 31, 2012	6,280,901
Vested and exercisable as of March 31, 2012 and expected to vest thereafter	8,943,053	[1]
Options Outstanding - Weighted-Average Exercise Price
Balance at December 31, 2011	$ 357.92
Exercised	$ 296.66
Forfeited/canceled	$ 399.16
Balance at March 31, 2012	$ 361.17
Vested and exercisable as of March 31, 2012	$ 323.19
Vested and exercisable as of March 31, 2012 and expected to vest thereafter	$ 358.40	[1]
Options Outstanding - Weighted-Average Remaining Contractual Term (in years)
Balance at March 31, 2012	5.4
Vested and exercisable as of March 31, 2012	4.4
Vested and exercisable as of March 31, 2012 and expected to vest thereafter	5.4	[1]
Options Outstanding - Average Intrinsic Value
Balance at March 31, 2012	$ 2,591	[2]
Vested and exercisable as of March 31, 2012	1,996	[2]
Vested and exercisable as of March 31, 2012 and expected to vest thereafter	$ 2,529	[1],[2]

[1] Options expected to vest reflect an estimated forfeiture rate.

[2] The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying awards and the closing stock price of $641.24 of our Class A common stock on March 30, 2012.