Hedging Activities (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
	Sep. 30, 2014	Sep. 30, 2014	Mar. 31, 2014
Foreign Exchange Contract [Member]
Derivative [Line Items]
Foreign currency derivative description		manage the impact of foreign currency fluctuation
Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Notional amount	$ 463	$ 463	$ 463
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Notional amount	1,325	1,325	1,091
Net gain (loss) from derivatives	30	50
Interest Rate Swap [Member]
Derivative [Line Items]
Interest rate derivative description		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]
Notional amount	$ 0	$ 0	$ 96
Minimum [Member] | Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Maturity dates		Mar. 31, 2015
Minimum [Member] | Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Maturity dates		Oct. 30, 2014
Maximum [Member] | Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Maturity dates		Mar. 31, 2020
Maximum [Member] | Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Maturity dates		Jun. 30, 2015