Segment Information (Schedule of Segment Information) (Details) - USD ($) $ in Millions	3 Months Ended
Jun. 30, 2015	Jun. 30, 2014
Segment Reporting Information [Line Items]
Segment reporting revenue from external customers	$ 47,546	$ 43,476
Distribution solutions	931	681
Interest Expense	(89)	(96)
Income from Continuing Operations Before Income Taxes	855	604
Assets, fair value adjustment		34
North America pharmaceutical distribution and services
Segment Reporting Information [Line Items]
Segment reporting revenue from external customers	39,532	34,304
International pharmaceutical distribution and services
Segment Reporting Information [Line Items]
Segment reporting revenue from external customers	5,838	7,025
Medical-Surgical distribution & services
Segment Reporting Information [Line Items]
Segment reporting revenue from external customers	1,440	1,379
Distribution solutions
Segment Reporting Information [Line Items]
Segment reporting revenue from external customers	46,810	42,708
Distribution solutions	910	$ 740
Proceeds from legal settlements	$ 59
Distribution solutions \| Maximum
Segment Reporting Information [Line Items]
Revenue derived from services, percentage	2.00%	2.00%
Technology solutions
Segment Reporting Information [Line Items]
Segment reporting revenue from external customers	$ 736	$ 768
Distribution solutions	158	68
Operating segments
Segment Reporting Information [Line Items]
Distribution solutions	1,068	808
Corporate
Segment Reporting Information [Line Items]
Corporate expenses, net	(124)	(108)
Nurse triage
Segment Reporting Information [Line Items]
Gain (Loss) on disposition of business	51
Nurse triage \| Technology solutions
Segment Reporting Information [Line Items]
Gain (Loss) on disposition of business	51
International Technology Workforce [Member] \| Cost of Sales [Member]
Segment Reporting Information [Line Items]
Assets, fair value adjustment		34
LIFO method of accounting [Member] \| Distribution solutions
Segment Reporting Information [Line Items]
Distribution solutions	$ 91	$ 98

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