Segment Information (Schedule Of Segment Information) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2011		Dec. 31, 2010
Revenues
Segment Reporting Revenue From External Customers	$ 30,839		$ 28,247		$ 91,035		$ 83,231
Operating profit
Interest Expense	(64)		(53)		(192)		(140)
Income from Continuing Operations Before Income Taxes	426		261		1,262		1,077
Technology Solutions [Member]
Revenues
Segment Reporting Revenue From External Customers	823		790		2,450		2,319
Operating profit
Operating profit	69	[1],[2],[3]	106	[1],[2],[3]	277	[1],[2],[3]	184	[1],[2],[3]
Technology Solutions - Services [Member]
Revenues
Segment Reporting Revenue From External Customers	643	[1]	629	[1]	1,916	[1]	1,828	[1]
Technology Solutions - Software And Software Systems [Member]
Revenues
Segment Reporting Revenue From External Customers	152		135		449		408
Technology Solutions - Hardware [Member]
Revenues
Segment Reporting Revenue From External Customers	28		26		85		83
Distribution Solutions [Member]
Revenues
Segment Reporting Revenue From External Customers	30,016	[4]	27,457	[4]	88,585	[4]	80,912	[4]
Operating profit
Operating profit	510	[5]	289	[5]	1,462	[5]	1,285	[5]
Distribution Solutions - Direct Distribution And Services [Member]
Revenues
Segment Reporting Revenue From External Customers	21,585	[4]	19,408	[4]	63,484	[4]	57,094	[4]
Distribution Solutions - Sales To Customers' Warehouses [Member]
Revenues
Segment Reporting Revenue From External Customers	5,198	[4]	4,731	[4]	14,998	[4]	14,133	[4]
Distribution Solutions - Domestic Pharmaceutical Distribution And Services [Member]
Revenues
Segment Reporting Revenue From External Customers	26,783	[4]	24,139	[4]	78,482	[4]	71,227	[4]
Distribution Solutions - Canada Pharmaceutical Distribution And Services [Member]
Revenues
Segment Reporting Revenue From External Customers	2,473	[4]	2,574	[4]	7,739	[4]	7,485	[4]
Distribution Solutions - Medical Surgical Distribution And Services [Member]
Revenues
Segment Reporting Revenue From External Customers	760	[4]	744	[4]	2,364	[4]	2,200	[4]
Corporate [Member]
Operating profit
Operating profit	(89)		(81)		(285)		(252)
Reportable Segment [Member]
Operating profit
Operating profit	$ 579		$ 395		$ 1,739		$ 1,469

[1] Revenues and operating profit for the quarter and nine months ended December 31, 2010 include the recognition of $23 million of revenue for a disease management contract for which the related expenses were previously recognized as incurred.

[2] Operating profit for the quarter and nine months ended December 31, 2011 includes charges of $42 million for a product alignment plan, of which $26 million and $16 million were recorded in cost of sales and operating expenses.

[3] Operating profit for the nine months ended December 31, 2010 includes a $72 million asset impairment charge for capitalized software held for sale, which was recorded in cost of sales.

[4] Revenues derived from services represent less than 2% of this segment's total revenues for the quarters and nine months ended December 31, 2011 and 2010.

[5] Operating profit includes AWP litigation charges of $27 million and $145 million for the quarter and nine months ended December 31, 2011 and $189 million and $213 million for the quarter and nine months ended December 31, 2010, which were recorded in operating expenses. Operating profit for the nine months ended December 31, 2010 includes the receipt of $51 million representing our share of a settlement of an antitrust class action lawsuit brought against a drug manufacturer, which was recorded as a reduction to cost of sales.