Segment Information Segment Information (Assets by Reportable Segment) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013		Jun. 30, 2013
Segment Reporting, Asset Reconciling Item
Assets	$ 25,009		$ 25,819
Pharmaceutical
Segment Reporting, Asset Reconciling Item
Assets	14,985	[1]	16,258
Medical
Segment Reporting, Asset Reconciling Item
Assets	6,558		6,521
Corporate
Segment Reporting, Asset Reconciling Item
Assets	$ 3,466		$ 3,040

[1] The decrease in Pharmaceutical segment assets is primarily due to the expiration of our pharmaceutical distribution contract with Walgreens.