Debt And Financing Activities (Accounts Receivable Sales Facility, Revolving Credit Facility and Commercial Paper) (Narrative) (Details)	12 Months Ended			1 Months Ended	12 Months Ended					9 Months Ended	12 Months Ended						2 Months Ended			12 Months Ended
	Mar. 31, 2014 USD ($)	Mar. 31, 2013 USD ($)	Mar. 31, 2012 USD ($)	Nov. 30, 2013 Accounts Receivable Sales Facility [Member]	Mar. 31, 2014 Accounts Receivable Sales Facility [Member] USD ($)	Mar. 31, 2013 Accounts Receivable Sales Facility [Member] USD ($)	Mar. 31, 2012 Accounts Receivable Sales Facility [Member] USD ($)	Nov. 30, 2013 Accounts Receivable Sales Facility [Member] Maximum [Member]	Oct. 31, 2013 Accounts Receivable Sales Facility [Member] Maximum [Member]	Dec. 31, 2013 Revolving Credit Facility [Member]	Mar. 31, 2014 Revolving Credit Facility [Member] USD ($)	Mar. 31, 2013 Revolving Credit Facility [Member] USD ($)	Mar. 31, 2012 Revolving Credit Facility [Member] USD ($)	Nov. 30, 2013 Revolving Credit Facility [Member] Maximum [Member]	Oct. 31, 2013 Revolving Credit Facility [Member] Maximum [Member]	Mar. 31, 2014 Revolving Credit Facility Due September Two Thousand Sixteen [Member] Unsecured Debt [Member] Revolving Credit Facility [Member] USD ($)	Mar. 31, 2014 Celesio [Member] Accounts Receivable Sales Facility [Member] USD ($)	Feb. 06, 2014 Celesio [Member] Accounts Receivable Sales Facility [Member] USD ($)	Mar. 31, 2014 Celesio [Member] Revolving Credit Facility [Member] EUR (€)	Mar. 31, 2014 Celesio [Member] 4.00 % Bonds Due October 18, 2016 [Member]	Mar. 31, 2013 Celesio [Member] 4.00 % Bonds Due October 18, 2016 [Member]	Mar. 31, 2014 Celesio [Member] 4.50% Bonds Due April 26, 2017 [Member]	Mar. 31, 2013 Celesio [Member] 4.50% Bonds Due April 26, 2017 [Member]
Line of Credit Facility [Line Items]
Interest rate on debt																				4.00%	4.00%	4.50%	4.50%
Debt Instrument, Maturity Date																				Oct. 18, 2016	Oct. 18, 2016	Apr. 26, 2017	Apr. 26, 2017
Repayments of Short-term Debt	$ 6,122,000,000	$ 2,625,000,000	$ 0
Line of Credit Facility, Expiration Period				1 year
Ratio of Indebtedness to Net Capital								0.65	0.565					0.65	0.565
Credit facility					1,350,000,000													308,000,000	500,000,000
Facility Expiration Date										Sep. 23, 2016
Proceeds from Lines of Credit					550,000,000	1,325,000,000	400,000,000				0	0	0				570,000,000
Borrowings Outstanding												0				0
Repayments of Lines of Credit					550,000,000	1,725,000,000	0										575,000,000
Pledged Assets, Not Separately Reported, Finance Receivables					0	0
Unsecured Debt											1,300,000,000
Delinquency Ratio For Qualifying Receivables						less than 1%
Issuance of commercial paper	0	0	0
Commercial paper amount outstanding	$ 0	$ 0