Accumulated Other Comprehensive Income - Changes in AOCI (Detail) - USD ($) $ in Millions		12 Months Ended
		May. 31, 2015		May. 31, 2014
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accumulated other comprehensive income balance at the beginning of the period		$ 85		$ 274
Other comprehensive gains (losses) before reclassifications, net of tax		1,460	[1]	(166)	[2]
Reclassifications to net income of previously deferred (gains) losses, net of tax		(299)	[3]	(23)	[4]
Other comprehensive income (loss)		1,161		(189)
Accumulated other comprehensive income balance at the end of the period		1,246		85
Other comprehensive income, before reclassification, tax benefit (expense)		(33)		9
Reclassification from accumulated other comprehensive income, tax (benefit) expense		2		9
Foreign Currency Translation Adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accumulated other comprehensive income balance at the beginning of the period	[5]	9	[6]	41
Other comprehensive gains (losses) before reclassifications, net of tax		(20)	[1],[6]	(32)	[2],[5]
Reclassifications to net income of previously deferred (gains) losses, net of tax		0	[3],[6]	0	[4],[5]
Other comprehensive income (loss)		(20)	[6]	(32)	[5]
Accumulated other comprehensive income balance at the end of the period	[6]	(11)		9	[5]
Other comprehensive income, before reclassification, tax benefit (expense)		0		0
Reclassification from accumulated other comprehensive income, tax (benefit) expense		0		0
Cash Flow Hedges
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accumulated other comprehensive income balance at the beginning of the period		32		193
Other comprehensive gains (losses) before reclassifications, net of tax		1,447	[1]	(134)	[2]
Reclassifications to net income of previously deferred (gains) losses, net of tax		(259)	[3]	(27)	[4]
Other comprehensive income (loss)		1,188		(161)
Accumulated other comprehensive income balance at the end of the period		1,220		32
Other comprehensive income, before reclassification, tax benefit (expense)		(33)		9
Reclassification from accumulated other comprehensive income, tax (benefit) expense		2		9
Net Investment Hedges
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accumulated other comprehensive income balance at the beginning of the period	[5]	95	[6]	95
Other comprehensive gains (losses) before reclassifications, net of tax		0	[1],[6]	0	[2],[5]
Reclassifications to net income of previously deferred (gains) losses, net of tax		0	[3],[6]	0	[4],[5]
Other comprehensive income (loss)		0	[6]	0	[5]
Accumulated other comprehensive income balance at the end of the period	[6]	95		95	[5]
Other comprehensive income, before reclassification, tax benefit (expense)		0		0
Reclassification from accumulated other comprehensive income, tax (benefit) expense		0		0
Other
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accumulated other comprehensive income balance at the beginning of the period		(51)		(55)
Other comprehensive gains (losses) before reclassifications, net of tax		33	[1]	0	[2]
Reclassifications to net income of previously deferred (gains) losses, net of tax		(40)	[3]	4	[4]
Other comprehensive income (loss)		(7)		4
Accumulated other comprehensive income balance at the end of the period		(58)		(51)
Other comprehensive income, before reclassification, tax benefit (expense)		0		0
Reclassification from accumulated other comprehensive income, tax (benefit) expense		$ 0		$ 0

[1] Net of tax benefit (expense) of $0 million, $(33) million, $0 million, $0 million and $(33) million, respectively.

[2] Net of tax benefit (expense) of $0 million, $9 million, $0 million, $0 million and $9 million, respectively.

[3] Net of tax (benefit) expense of $0 million, $2 million, $0 million, $0 million and $2 million, respectively.

[4] Net of tax (benefit) expense of $0 million, $9 million, $0 million, $0 million and $9 million respectively.

[5] The accumulated foreign currency translation adjustment and net investment hedge gains/losses related to an investment in a foreign subsidiary are reclassified to Net income upon sale or upon complete or substantially complete liquidation of the respective entity.

[6] The accumulated foreign currency translation adjustment and net investment hedge gains/losses related to an investment in a foreign subsidiary are reclassified to Net income upon sale or upon complete or substantially complete liquidation of the respective entity.