Hedging Activities (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Jun. 30, 2014	Mar. 31, 2014
Foreign Exchange Contract [Member]
Derivative [Line Items]
Description of Foreign Currency Derivative Activities	manage the impact of foreign currency fluctuation
Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 463	$ 463
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Notional Amount	1,449	1,091
Interest Rate Swap [Member]
Derivative [Line Items]
Description of Interest Rate Derivative Activities	hedge the interest rate risk associated with Celesio’s variable rate debt
Interest Rate Swap [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 68	$ 96
Derivative, Maturity Date	Sep. 30, 2014
Minimum [Member] | Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Maturity of Foreign Currency Derivatives	Mar. 31, 2015
Minimum [Member] | Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Maturity of Foreign Currency Derivatives	Jul. 31, 2014
Maximum [Member] | Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Maturity of Foreign Currency Derivatives	Mar. 31, 2020
Maximum [Member] | Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Maturity of Foreign Currency Derivatives	Jun. 30, 2015