Subsequent Events - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended		3 Months Ended		1 Months Ended
	Dec. 07, 2012	Nov. 28, 2012 Subsequent Event	Feb. 25, 2013 Subsequent Event	Dec. 07, 2012 Subsequent Event	Dec. 07, 2012 Subsequent Event 0.650% Senior Notes due December 7, 2015	Dec. 07, 2012 Subsequent Event 0.650% Senior Notes due December 7, 2015 First Payment	Dec. 07, 2012 Subsequent Event 1.125% Senior Notes due December 15, 2017	Dec. 07, 2012 Subsequent Event 1.125% Senior Notes due December 15, 2017 First Payment	Dec. 07, 2012 Subsequent Event 1.700% Senior Notes due December 15, 2019	Dec. 07, 2012 Subsequent Event 1.700% Senior Notes due December 15, 2019 First Payment	Nov. 28, 2012 Subsequent Event 401(k) Retirement Plan
Subsequent Event [Line Items]
Special cash dividend declared, per share		$ 7.00
Special dividend paid		$ 3,049
Special cash dividend declared, declared date		Nov. 28, 2012
Special cash dividend declared, payable date		Dec. 18, 2012
Special cash dividend declared, record date		Dec. 10, 2012
Ownership of employee, shares											22,600,000
Discrete income tax benefit			62
Senior note				3,500	1,200		1,100		1,200
Senior note, interest rate					0.65%		1.125%		1.70%
Debt instrument frequency of periodic payment					Interest is due semi-annually on June 7 and December 7, with the first payment due on June 7, 2013		Interest is due semi-annually on June 15 and December 15, with the first payment due on June 15, 2013		Interest is due semi-annually on June 15 and December 15, with the first payment due on June 15, 2013
Debt instrument maturity date						Jun. 07, 2013		Jun. 15, 2013		Jun. 15, 2013
General corporate expense	$ 450