Segment Information (Revenue by Reportable Segment) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Sep. 30, 2013		Sep. 30, 2012
Segment Reporting Information
Revenue	$ 24,523		$ 25,889
Pharmaceutical
Segment Reporting Information
Revenue	21,813	[1]	23,498
Pharmaceutical | Walgreens Co
Segment Reporting Information
Contract expiration date	Aug. 31, 2013
Pharmaceutical | Express Scripts, Inc
Segment Reporting Information
Contract expiration date			Sep. 30, 2012
Medical
Segment Reporting Information
Revenue	2,711		2,393
Reportable Segments
Segment Reporting Information
Revenue	24,524		25,891
Corporate
Segment Reporting Information
Revenue	$ (1)	[2]	$ (2)	[2]

[1] The decrease in Pharmaceutical segment revenue is primarily due to the expiration of our pharmaceutical distribution contracts with Walgreen Co. ("Walgreens") on August 31, 2013 and Express Scripts, Inc. on September 30, 2012.

[2] Corporate revenue consists of the elimination of inter-segment revenue.