Business Combinations (Narrative) (Details) Share data in Millions, except Per Share data, unless otherwise specified	12 Months Ended			0 Months Ended	3 Months Ended	12 Months Ended				0 Months Ended		0 Months Ended			12 Months Ended
	Mar. 31, 2015 USD ($)	Mar. 31, 2014 USD ($)	Mar. 31, 2013 USD ($)	Feb. 06, 2014 Celesio [Member] USD ($)	Mar. 31, 2014 Celesio [Member] USD ($)	Mar. 31, 2015 Celesio [Member] USD ($)	Mar. 31, 2015 Celesio [Member] EUR (€)	Dec. 31, 2014 Celesio [Member] EUR (€)	Feb. 06, 2014 Celesio [Member] USD ($)	Feb. 22, 2013 PSS World Medical [Member] USD ($)	Feb. 22, 2013 PSS World Medical [Member] USD ($)	Apr. 06, 2012 Corporate Headquarters [Member] USD ($)	Apr. 06, 2012 Corporate Headquarters [Member] USD ($)	Apr. 06, 2012 Fair Value, Inputs, Level 2 [Member] Corporate Headquarters [Member] USD ($)	Mar. 31, 2015 Fair Value, Inputs, Level 3 [Member] Celesio [Member] USD ($)	Feb. 22, 2013 Fair Value, Inputs, Level 3 [Member] PSS World Medical [Member] USD ($)
Business Acquisition [Line Items]
Effective Date of Acquisition				Feb. 06, 2014						Feb. 22, 2013		Apr. 06, 2012
Percentage of Voting Interests Acquired									77.60%
Name of Acquired Entity				Celesio AG						PSS World Medical, Inc. (“PSSI”)
Per Share Price of Outstanding Shares Acquired											$ 29.00
Purchase Price for Acquisition										$ 1,900,000,000
Cash Paid for Acquisition				4,500,000,000						1,300,000,000		90,000,000
Business Acquisition Percentage Of Voting Interests Acquired Fully Diluted									75.60%
Business Combination, Debt Assumed				2,300,000,000						600,000,000
Description of Acquired Entity				Celesio is an international wholesale and retail company and a provider of logistics and services to the pharmaceutical and healthcare sectors. Celesio’s headquarters is in Stuttgart, Germany and it operates in 14 countries around the world.						PSSI markets and distributes medical products and services throughout the United States.
Debt Conversion, Converted Instrument, Shares Issued					20.9
Convertible bond redemption, cash proceeds					30,000,000
NCI ownership interest, parent					75.40%
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles						709,000,000									709,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles						2,309,000,000			3,018,000,000							568,000,000
Annual Recurring Compensation to NCI Under Domination Agreement, Per Share							€ 0.83
Guaranteed Dividend								€ 0.83
Put right price per share							€ 22.99
Put Right Interest Rate						5.00%
Goodwill	9,817,000,000	9,927,000,000	6,405,000,000			4,225,000,000			3,570,000,000		1,149,000,000
Currently Acquired Percentage of Building													50.00%
Previously Held Percentage of Building													50.00%
Gain on business combination	0	0	81,000,000									81,000,000
Business combination gain, after-tax												51,000,000
Net assets, fair value													180,000,000
Building, fair value													113,000,000
Land, fair value														$ 58,000,000