Summary of Significant Accounting Policies - Revisions (Details) (USD $)	12 Months Ended						12 Months Ended			12 Months Ended
	May 31, 2014	May 31, 2013	May 31, 2012	May 31, 2013 Prior Year Revision As Reported	May 31, 2012 Prior Year Revision As Reported	May 31, 2010 Prior Year Revision As Reported	May 31, 2013 Prior Year Revision Adjustment	May 31, 2012 Prior Year Revision Adjustment	May 31, 2010 Prior Year Revision Adjustment	May 31, 2013 Prior Year Revision to Inventory Amounts Adjustment	May 31, 2012 Prior Year Revision to Inventory Amounts Adjustment	May 31, 2013 Prior Period Revisions to Non-cash Property Plant And Equipment Additions Adjustment	May 31, 2012 Prior Period Revisions to Non-cash Property Plant And Equipment Additions Adjustment	May 31, 2014 Retained Earnings	May 31, 2013 Retained Earnings	May 31, 2012 Retained Earnings	May 31, 2013 Retained Earnings Prior Year Revision As Reported	May 31, 2012 Retained Earnings Prior Year Revision As Reported	May 31, 2010 Retained Earnings Prior Year Revision As Reported	May 31, 2013 Retained Earnings Prior Year Revision Adjustment	May 31, 2012 Retained Earnings Prior Year Revision Adjustment	May 31, 2010 Retained Earnings Prior Year Revision Adjustment
Net Income (Loss) [Abstract]
Total selling and administrative expense	$ 8,766,000,000	$ 7,796,000,000	$ 7,079,000,000	$ 7,780,000,000	$ 7,065,000,000		$ 16,000,000	$ 14,000,000
Income before income taxes	3,544,000,000	3,256,000,000	3,011,000,000	3,272,000,000	3,025,000,000		(16,000,000)	(14,000,000)
Income tax expense	851,000,000	805,000,000	754,000,000	808,000,000	756,000,000		(3,000,000)	(2,000,000)
NET INCOME FROM CONTINUING OPERATIONS	2,693,000,000	2,451,000,000	2,257,000,000	2,464,000,000	2,269,000,000		(13,000,000)	(12,000,000)
Net income	2,693,000,000	2,472,000,000	2,211,000,000	2,485,000,000	2,223,000,000		(13,000,000)	(12,000,000)						2,693,000,000	2,472,000,000	2,211,000,000
Basic earnings per common share (in dollars per share)	$ 3.05	$ 2.74	$ 2.45	$ 2.75	$ 2.47		$ (0.01)	$ (0.02)
Diluted earnings per common share (in dollars per share)	$ 2.97	$ 2.68	$ 2.40	$ 2.69	$ 2.42		$ (0.01)	$ (0.02)
Basic earnings per common share (in dollars per share)	$ 3.05	$ 2.76	$ 2.40	$ 2.77	$ 2.42		$ (0.01)	$ (0.02)
Diluted earnings per common share (in dollars per share)	$ 2.97	$ 2.70	$ 2.35	$ 2.71	$ 2.37		$ (0.01)	$ (0.02)
Comprehensive Income [Abstract]
Net income	2,693,000,000	2,472,000,000	2,211,000,000	2,485,000,000	2,223,000,000		(13,000,000)	(12,000,000)						2,693,000,000	2,472,000,000	2,211,000,000
TOTAL COMPREHENSIVE INCOME	2,504,000,000	2,597,000,000	2,265,000,000	2,610,000,000	2,277,000,000		(13,000,000)	(12,000,000)
ASSETS
Inventories	3,947,000,000	3,484,000,000		3,434,000,000			50,000,000
Prepaid expenses and other current assets	818,000,000	756,000,000		802,000,000			(46,000,000)
Total current assets	13,696,000,000	13,630,000,000		13,626,000,000			4,000,000
Identifiable intangible assets, net	282,000,000	289,000,000		382,000,000			(93,000,000)
Deferred income taxes and other assets	1,651,000,000	1,043,000,000		993,000,000			50,000,000
Assets	18,594,000,000	17,545,000,000		17,584,000,000			(39,000,000)
LIABILITIES AND SHAREHOLDERS’ EQUITY
TOTAL NOTES PAYABLE	167,000,000	98,000,000		121,000,000			(23,000,000)
Accounts payable	1,930,000,000	1,669,000,000		1,646,000,000			23,000,000
Accrued liabilities	2,491,000,000	2,036,000,000		1,986,000,000			50,000,000
Income taxes payable	432,000,000	84,000,000		98,000,000			(14,000,000)
Total current liabilities	5,027,000,000	3,962,000,000		3,926,000,000			36,000,000
Retained earnings	4,871,000,000	5,620,000,000		5,695,000,000			(75,000,000)
Total shareholders’ equity	10,824,000,000	11,081,000,000	10,319,000,000	11,156,000,000	10,381,000,000	9,843,000,000	(75,000,000)	(62,000,000)	(50,000,000)					4,871,000,000	5,620,000,000	5,526,000,000	5,695,000,000	5,588,000,000	5,801,000,000	(75,000,000)	(62,000,000)	(50,000,000)
TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY	18,594,000,000	17,545,000,000		17,584,000,000			(39,000,000)
Cash provided by operations:
Net income	2,693,000,000	2,472,000,000	2,211,000,000	2,485,000,000	2,223,000,000		(13,000,000)	(12,000,000)						2,693,000,000	2,472,000,000	2,211,000,000
Deferred income taxes	(11,000,000)	20,000,000	(59,000,000)	21,000,000	(60,000,000)		(1,000,000)	1,000,000
Amortization and other	114,000,000	66,000,000	23,000,000	75,000,000	32,000,000		(9,000,000)	(9,000,000)
(Increase) in inventories	(505,000,000)	(219,000,000)	(815,000,000)	(197,000,000)	(805,000,000)		(22,000,000)	(10,000,000)
Increase in accounts payable, accrued liabilities and income taxes payable	525,000,000	27,000,000	425,000,000	41,000,000	470,000,000		(14,000,000)	(45,000,000)
Cash provided by operations	3,003,000,000	2,968,000,000	1,824,000,000	3,027,000,000	1,899,000,000		(59,000,000)	(75,000,000)
Cash (used) provided by investing activities:
Purchases of short-term investments	(5,386,000,000)	(4,133,000,000)	(3,245,000,000)	(3,702,000,000)	(2,705,000,000)		(431,000,000)	(540,000,000)
Maturities of short-term investments	3,932,000,000	1,663,000,000	2,663,000,000	1,501,000,000	2,585,000,000		162,000,000	78,000,000
Sales of short-term investments	1,126,000,000	1,330,000,000	1,721,000,000	998,000,000	1,244,000,000		332,000,000	477,000,000
Additions to property, plant and equipment	(880,000,000)	(598,000,000)	(563,000,000)	(636,000,000)	(597,000,000)		38,000,000	34,000,000
Increase in other assets, net of other liabilities	(2,000,000)	(2,000,000)	(14,000,000)	(28,000,000)	(37,000,000)		26,000,000	23,000,000
Cash (used) provided by investing activities	(1,207,000,000)	(940,000,000)	586,000,000	(1,067,000,000)	514,000,000		127,000,000	72,000,000
Cash used by financing activities:
Increase (decrease) in notes payable	75,000,000	10,000,000	(47,000,000)	15,000,000	(65,000,000)		(5,000,000)	18,000,000
Cash used by financing activities	(2,914,000,000)	(1,045,000,000)	(2,100,000,000)	(1,040,000,000)	(2,118,000,000)		(5,000,000)	18,000,000
Net (decrease) increase in cash and equivalents	(1,117,000,000)	1,083,000,000	377,000,000	1,020,000,000	362,000,000		63,000,000	15,000,000		0
Cash and equivalents, beginning of year	3,337,000,000	2,254,000,000	1,877,000,000	2,317,000,000	1,955,000,000		(63,000,000)	(78,000,000)
CASH AND EQUIVALENTS, END OF YEAR	2,220,000,000	3,337,000,000	2,254,000,000	3,337,000,000	2,317,000,000		0	(63,000,000)
Cash provided (used) by operations, adjustment							26,000,000	(23,000,000)		0	0	38,000,000	34,000,000
Cash provided (used) by investing activities, adjustment							26,000,000	(23,000,000)
Increase in accrued liabilities							50,000,000
Statement of Stockholders' Equity [Abstract]
Beginning Balance	11,081,000,000	10,319,000,000	9,793,000,000	10,381,000,000		9,843,000,000	(62,000,000)		(50,000,000)					5,620,000,000	5,526,000,000	5,751,000,000	5,695,000,000	5,588,000,000	5,801,000,000	(75,000,000)	(62,000,000)	(50,000,000)
Net income	2,693,000,000	2,472,000,000	2,211,000,000	2,485,000,000	2,223,000,000		(13,000,000)	(12,000,000)						2,693,000,000	2,472,000,000	2,211,000,000
Ending Balance	$ 10,824,000,000	$ 11,081,000,000	$ 10,319,000,000	$ 11,156,000,000	$ 10,381,000,000	$ 9,843,000,000	$ (75,000,000)	$ (62,000,000)	$ (50,000,000)					$ 4,871,000,000	$ 5,620,000,000	$ 5,526,000,000	$ 5,695,000,000	$ 5,588,000,000	$ 5,801,000,000	$ (75,000,000)	$ (62,000,000)	$ (50,000,000)