Retirement Plans (Details 4) (USD $) In Millions, unless otherwise specified	12 Months Ended
May 31, 2014	May 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 21,444	$ 19,047
Quoted Prices In Active Markets Level 1	3,141	3,614
Other Observable Inputs Level 2	18,027	15,101
Unobservable Inputs Level 3	276	332
Cash And Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	313	456
Actual %	2.00%	2.00%
Target %	0 - 5%	0 - 5%
Quoted Prices In Active Markets Level 1	55	15
Other Observable Inputs Level 2	258	441
U.S. Large Cap Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	5,196	5,264
Actual %	24.00%	28.00%
Quoted Prices In Active Markets Level 1	55	37
Other Observable Inputs Level 2	5,141	5,227
U.S. SMID Cap Equity
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	886	1,741
Actual %	4.00%	9.00%
Quoted Prices In Active Markets Level 1	886	1,741
International Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,652	2,271
Actual %	12.00%	12.00%
Quoted Prices In Active Markets Level 1	2,206	1,904
Other Observable Inputs Level 2	446	367
Global Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,367
Actual %	7.00%
Other Observable Inputs Level 2	1,367
Private Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	276	332
Actual %	1.00%	2.00%
Unobservable Inputs Level 3	276	332
Total Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target %	35 - 55%	35 - 55%
Corporate Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	5,758	4,972
Actual %	27.00%	26.00%
Other Observable Inputs Level 2	5,758	4,972
Government Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	4,782	3,888
Actual %	22.00%	20.00%
Other Observable Inputs Level 2	4,782	3,888
Mortgage Backed And Other Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	275	200
Actual %	1.00%	1.00%
Other Observable Inputs Level 2	275	200
Total Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target %	45 - 65%	45 - 65%
Other Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	(61)	(77)
Quoted Prices In Active Markets Level 1	(61)	(83)
Other Observable Inputs Level 2		$ 6
Total Asset Class [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual %	100.00%	100.00%

- Definition

This item represents the amount of assets or liabilities, including financial instruments, which are measured at fair value on either a recurring or nonrecurring basis and fall within Level 2 of the fair value measurements hierarchy. Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. Level 2 inputs include the following: (a) quoted prices for similar assets or liabilities in active markets; (b) quoted prices for identical or similar assets or liabilities in markets that are not active, that is, markets in which there are few transactions for the asset or liability, the prices are not current, or price quotations vary substantially either over time or among market makers (for example, some brokered markets), or in which little information is released publicly (for example, a principal-to-principal market); (c) inputs other than quoted prices that are observable for the asset or liability (for example, interest rates and yield curves observable at commonly quoted intervals, volatilities, prepayment speeds, loss severities, credit risks, and default rates); or (d) inputs that are derived principally from or corroborated by observable market data by correlation or other means (market-corroborated inputs).

+ References+ Details