Debt (Additional Information) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended			12 Months Ended				12 Months Ended		12 Months Ended		12 Months Ended
	Aug. 31, 2014 Senior Notes Zero Point Nine Two Percent Due July Eighth Twenty Twenty-Four [Member] [Domain]	Jul. 08, 2014 Senior Notes Zero Point Nine Two Percent Due July Eighth Twenty Twenty-Four [Member] [Domain]	Jul. 08, 2014 Closing [Member]	Aug. 31, 2014 Senior Notes Five Point Five Percent Due March Twenty Seventeen [Member]	Feb. 28, 2007 Senior Notes Five Point Five Percent Due March Twenty Seventeen [Member]	Dec. 07, 2012 Senior Notes [Member]	Feb. 28, 2007 Senior Notes [Member]	Aug. 31, 2014 0.65% Senior Notes due December 2015	Dec. 07, 2012 0.65% Senior Notes due December 2015	Aug. 31, 2014 Senior Notes One Point One Two Five Percent Due December Fifteen Twenty Seventeen [Member]	Dec. 07, 2012 Senior Notes One Point One Two Five Percent Due December Fifteen Twenty Seventeen [Member]	Aug. 31, 2014 Senior Notes One Point Seven Percent Due December Twenty Nineteen [Member]	Dec. 07, 2012 Senior Notes One Point Seven Percent Due December Twenty Nineteen [Member]
Debt Instrument [Line Items]
Senior note						$ 3,500			$ 1,200		$ 1,100		$ 1,200
Senior note, interest rate									0.65%		1.125%		1.70%
Debt Instrument, Maturity Date	Jul. 08, 2024			Mar. 15, 2017				Dec. 07, 2015		Dec. 15, 2017		Dec. 15, 2019
Debt Instrument, Face Amount		117			1,100
Debt instrument, stated interest rate (percent)			0.92%		5.50%
Debt Instrument, Unamortized Discount					$ 6
Redemption Price Company Option						100.00%	100.00%
Redemption Price Certain Events						101.00%	101.00%