Stockholders' Equity - Additional Information (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		1 Months Ended	3 Months Ended		6 Months Ended
	Jun. 30, 2011 Year	Dec. 31, 2010	Jun. 30, 2011 Restricted Stock Units	Jun. 30, 2011 Restricted Stock Units	Jun. 30, 2010 Restricted Stock Units	Jun. 30, 2011 Restricted Stock Units	Jun. 30, 2010 Restricted Stock Units
Stockholders Equity Note [Line Items]
Restricted stock units granted, common stock			2.0	2.8	1.5	3.5	3.9
Restricted stock units granted, per share weighted average fair value				$ 187.32	$ 137.78	$ 184.28	$ 135.51
Common shares outstanding plus shares underlying outstanding stock awards, including all stock-based awards outstanding, including estimated forfeiture	468	465
Net unrecognized compensation cost related to unvested stock-based compensation arrangements	$ 850
Net unrecognized compensation cost related to unvested stock-based compensation arrangements, weighted average recognition period (in years)	1.3