Debt and Financing Activities Debt and Financing Activities (Celesio Debt Acquired) (Details) Share data in Millions, unless otherwise specified			1 Months Ended	12 Months Ended								3 Months Ended			3 Months Ended								2 Months Ended		0 Months Ended				2 Months Ended
	Mar. 31, 2014 USD ($)	Mar. 31, 2013 USD ($)	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 ($)	Mar. 31, 2014 Revolving Credit Facility [Member] USD ($)	Mar. 31, 2013 Revolving Credit Facility [Member] USD ($)	Mar. 31, 2012 Revolving Credit Facility [Member] USD ($)	Mar. 31, 2014 Celesio [Member]	Feb. 06, 2014 Celesio [Member] USD ($)	Mar. 31, 2014 Celesio [Member] The 2018 Bonds [Member] convertiblebond	Mar. 31, 2014 Celesio [Member] Line of Credit [Member] USD ($)	Mar. 31, 2014 Celesio [Member] Long-term Debt [Member] USD ($)	Mar. 31, 2014 Celesio [Member] The 2014 Bonds [Member] convertiblebond	Mar. 31, 2014 Celesio [Member] The 2014 and 2018 Bonds [Member]	Mar. 31, 2014 Celesio [Member] Promissory Notes [Member] USD ($)	Mar. 31, 2013 Celesio [Member] Promissory Notes [Member] USD ($)	Mar. 31, 2014 Celesio [Member] 4.00 % Bonds Due October 18, 2016 [Member] USD ($)	Mar. 31, 2013 Celesio [Member] 4.00 % Bonds Due October 18, 2016 [Member] USD ($)	Mar. 31, 2014 Celesio [Member] 4.50% Bonds Due April 26, 2017 [Member] USD ($)	Mar. 31, 2013 Celesio [Member] 4.50% Bonds Due April 26, 2017 [Member] USD ($)	Mar. 31, 2014 Celesio [Member] Minimum [Member] Promissory Notes [Member]	Mar. 31, 2014 Celesio [Member] Maximum [Member] Promissory Notes [Member]	Feb. 06, 2014 Celesio [Member] Third Party Investors [Member] The 2018 Bonds [Member] convertiblebond	Feb. 06, 2014 Celesio [Member] Third Party Investors [Member] The 2014 Bonds [Member] convertiblebond	Mar. 31, 2014 Celesio [Member] Third Party Investors [Member] The 2014 and 2018 Bonds [Member] USD ($)	Feb. 06, 2014 Celesio [Member] Third Party Investors [Member] The 2014 and 2018 Bonds [Member] USD ($)	Mar. 31, 2014 Celesio [Member] Accounts Receivable Sales Facility [Member] USD ($)	Feb. 06, 2014 Celesio [Member] Accounts Receivable Sales Facility [Member] USD ($)	Mar. 31, 2014 Celesio [Member] Secured Debt [Member] USD ($)	Mar. 31, 2014 Celesio [Member] Revolving Credit Facility [Member] EUR (€)	Mar. 31, 2014 Revolving Credit Facility Due February Two Thousand Eighteen [Member] Celesio [Member] Revolving Credit Facility [Member] Unsecured Debt [Member] USD ($)	Mar. 31, 2014 Variable Interest Rate [Member] Celesio [Member] USD ($)	May 07, 2014 Subsequent Event [Member] USD ($)	Mar. 31, 2014 Corporate Bond Securities [Member] Celesio [Member] USD ($)	May 07, 2014 Corporate Bond Securities [Member] Subsequent Event [Member] Celesio [Member] USD ($)
Debt Instrument [Line Items]
Credit facility				$ 1,350,000,000																										$ 308,000,000		€ 500,000,000
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum																													1.33%
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Maximum																													2.31%
Proceeds from Lines of Credit				550,000,000	1,325,000,000	400,000,000	0	0	0																				570,000,000
Repayments of Lines of Credit				550,000,000	1,725,000,000	0																							575,000,000
Borrowings Outstanding								0																							246,000,000		0
Bilateral credit line											1,662,000,000
Short-term borrowings	346,000,000	0																																100,000,000
Long-term Debt, Percentage Bearing Variable Interest, Amount													88,000,000	100,000,000
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate	0.64%									2.35%
Convertible bonds acquired												2,180			4,840										1,104	1,857
Convertible Debt																											5,000,000	344,000,000
Interest rate on debt																			4.00%	4.00%	4.50%	4.50%	1.23%	5.35%
Line of Credit Facility, Expiration Period			1 year																				4 years	7 years
Other long-term debt																	297,000,000	0
Debt Conversion, Converted Instrument, Shares Issued												11.4				11.9
Long-term debt	10,373,000,000	4,873,000,000																	507,000,000	0	737,000,000	0
Long-term Debt, Current Maturities																																				1,244,000,000
Long-term Debt, Fair Value																																					1,272,000,000
Corporate Bond Aggregate Par Value																																			$ 1,184,000,000