Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
Nov. 30, 2011	Nov. 30, 2010	Nov. 30, 2011	Nov. 30, 2010
Reconciliation of Net Income to Comprehensive Income [Abstract]
Net income	$ 497	$ 283	$ 961	$ 663
Other comprehensive income:
Foreign currency translation adjustments, net of tax	(110)	44	(91)	72
Amortization of unrealized pension actuarial gains/losses and other, net of tax	30	26	60	52
Comprehensive income	417	353	930	787
Other Comprehensive Income/Loss, Tax Amounts
Foreign currency translation adjustments, tax	26	11	22	17
Amortization of unrealized pension actuarial gains/losses and other, tax	$ 18	$ 15	$ 36	$ 31

The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the reporting entity. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, but excludes any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent.

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-Glossary Other Comprehensive Income

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+ Details

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

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+ Details

- Definition

The increase (decrease) in accumulated comprehensive income during the period related to pension and other postretirement benefit plans, after tax. While for technical reasons this element has no balance attribute, the default assumption is a credit balance consistent with its label.

+ References+ Details

- Definition

Tax effects of the increase (decrease) to accumulated comprehensive income during the period related to benefit plans. While for technical reasons this element has no balance attribute, the default assumption is a credit balance consistent with its label.

+ References+ Details

- Definition

Adjustment that results from the process of translating subsidiary financial statements and foreign equity investments into the reporting currency of the reporting entity, net of tax.

+ References

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+ Details

- Definition

Tax effect of the adjustment that results from the process of translating subsidiary financial statements and foreign equity investments into functional currency of the reporting entity. While for technical reasons this element has no balance attribute, the default assumption is a credit balance consistent with its label.

+ References+ Details