Debt And Financing Activities (Accounts Receivable Facilities, Revolving Credit Facilities and Lines of Credit) (Narrative) (Details)	12 Months Ended		12 Months Ended												12 Months Ended
	Mar. 31, 2015 Bilateral Lines of Credit [Member] USD ($)	Mar. 31, 2014 Bilateral Lines of Credit [Member] USD ($)	Mar. 31, 2015 Accounts Receivable Sales Facility [Member] USD ($)	Mar. 31, 2014 Accounts Receivable Sales Facility [Member] USD ($)	Mar. 31, 2013 Accounts Receivable Sales Facility [Member] USD ($)	Mar. 31, 2015 Accounts Receivable Factoring Facility [Member] USD ($)	Mar. 31, 2014 Accounts Receivable Factoring Facility [Member] USD ($)	Mar. 31, 2015 Revolving Credit Facility [Member] USD ($)	Mar. 31, 2014 Revolving Credit Facility [Member] USD ($)	Mar. 31, 2013 Revolving Credit Facility [Member] USD ($)	Mar. 31, 2014 Foreign Line of Credit [Member] USD ($)	Mar. 31, 2015 Celesio [Member] Revolving Credit Facility [Member] USD ($)	Mar. 31, 2014 Celesio [Member] Revolving Credit Facility [Member] USD ($)	Mar. 31, 2015 Celesio [Member] Revolving Credit Facility [Member] EUR (€)	Mar. 31, 2015 Floating Rate Notes Due September 10, 2015 [Member]	Mar. 31, 2014 Floating Rate Notes Due September 10, 2015 [Member]
Line of Credit Facility [Line Items]
Debt maturity date															Sep. 10, 2015	Sep. 10, 2015
Credit facility expiration period			2 years
Credit facility borrowing capacity	$ 1,400,000,000		$ 1,350,000,000			$ 169,000,000		$ 1,300,000,000						€ 500,000,000
Credit facility expiration date			Nov. 30, 2016			Jan. 31, 2016		Sep. 23, 2016				Feb. 28, 2018
Proceeds from lines of credit	225,000,000		0	550,000,000	1,325,000,000	2,875,000,000	570,000,000	0	0	0	0	0	0
Repayments of lines of credit	267,000,000		0	550,000,000	1,725,000,000	2,908,000,000	575,000,000
Other Short-term Borrowings	29,000,000	65,000,000	0	0		135,000,000	246,000,000
Pledged Assets, Not Separately Reported, Finance Receivables			0	0		135,000,000	246,000,000
Credit facility outstanding, long-term								$ 0	$ 0		$ 0	$ 0	$ 0
Interest rate, minimum	0.20%					0.85%
Interest rate, maximum	6.00%					1.26%