Other Commitments And Contingent Liabilities (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended						12 Months Ended			0 Months Ended	1 Months Ended	12 Months Ended				1 Months Ended	12 Months Ended
	Mar. 31, 2012 site claim	Mar. 31, 2011	Mar. 31, 2010	Mar. 31, 2012 Northstar Rx LLC [Member] claim	Mar. 31, 2012 McKesson Medical-Surgical Inc [Member] claim	Mar. 31, 2012 Distributor [Member] claim	Mar. 31, 2012 Reglan [Member] plaintiff	Mar. 31, 2012 Other Litigation and Claims [Member]	Mar. 31, 2012 Previous Cases [Member]	Oct. 25, 2011 Average Wholesale Price Litigation [Member]	Apr. 30, 2012 Average Wholesale Price Litigation [Member]	Mar. 31, 2012 Average Wholesale Price Litigation [Member]	Mar. 31, 2011 Average Wholesale Price Litigation [Member]	Mar. 31, 2010 Average Wholesale Price Litigation [Member]	Mar. 31, 2012 Average Wholesale Price Litigation [Member] State Attorneys General [Member]	Nov. 30, 2010 Distribution Solutions [Member] Average Wholesale Price Litigation [Member]	Mar. 31, 2012 Maximum [Member] Other Litigation and Claims [Member]	Mar. 31, 2012 Minimum [Member] Other Litigation and Claims [Member]
Loss Contingencies [Line Items]
Remediation costs	$ 7.0
Amount third parties have agreed to pay in settlement	1.7
Chemical conditions sites, number	8
Hazardous substance sites, number	13
Estimated loss	1.0
Cases pending				425	7	850
Additional cases pending	52
Number of plaintiffs							2,000
Damages sought								82	6	82						101
Fines and penalties sought																112
Loss contingency fines and penalties sought value									18								814	407
Settlement expense paid till date												32
Loss contingency settlement agreement															173
Cash payments for legal settlement	26	26	350								191	26	26	0
Estimated environmental assessment and cleanup costs	$ 70
Remediation costs expected to be paid out, period	April 2012 and March 2032