Business Combinations (Narrative) (Details)	2 Months Ended	3 Months Ended	12 Months Ended			0 Months Ended		2 Months Ended	3 Months Ended		3 Months Ended			1 Months Ended	3 Months Ended	12 Months Ended		3 Months Ended				3 Months Ended	1 Months Ended	3 Months Ended	12 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended																						3 Months Ended	12 Months Ended
	Mar. 31, 2014 USD ($)	Mar. 31, 2014 USD ($)	Mar. 31, 2014 USD ($)	Mar. 31, 2013 USD ($)	Mar. 31, 2012 USD ($)	Feb. 06, 2014 Celesio [Member] USD ($)	Feb. 06, 2014 Celesio [Member] EUR (€)	Mar. 31, 2014 Celesio [Member]	Mar. 31, 2014 Celesio [Member] USD ($)	Feb. 28, 2014 Celesio [Member] EUR (€)	Mar. 31, 2014 Celesio [Member] Trademarks [Member]	Mar. 31, 2014 Celesio [Member] Customer Relationships [Member]	Mar. 31, 2014 Celesio [Member] Pharmacy Licenses [Member]	Feb. 28, 2013 PSS World Medical [Member] USD ($)	Mar. 31, 2014 PSS World Medical [Member]	Mar. 31, 2014 PSS World Medical [Member] USD ($)	Feb. 22, 2013 PSS World Medical [Member] USD ($)	Mar. 31, 2014 PSS World Medical [Member] Customer Relationships [Member]	Mar. 31, 2014 PSS World Medical [Member] Trademarks and Trade Names [Member]	Jun. 30, 2012 Corporate Headquarters [Member] USD ($)	Apr. 06, 2012 Corporate Headquarters [Member] USD ($)	Jun. 30, 2012 Corporate Headquarters [Member] Building and Building Improvements [Member]	Mar. 31, 2012 Katz Group [Member] USD ($)	Sep. 30, 2012 Katz Group [Member]	Mar. 31, 2012 Katz Group [Member] USD ($)	Mar. 31, 2012 Katz Group [Member] Amounts Recognized As Of Acquisition Date As Adjusted [Member] USD ($)	Mar. 31, 2014 The 2014 Bonds [Member] Celesio [Member] convertiblebond	Feb. 06, 2014 The 2014 Bonds [Member] Celesio [Member] EUR (€)	Mar. 31, 2014 The 2018 Bonds [Member] Celesio [Member] convertiblebond	Feb. 06, 2014 The 2018 Bonds [Member] Celesio [Member] EUR (€)	Mar. 31, 2014 The 2014 and 2018 Bonds [Member] Celesio [Member] USD ($)	Mar. 31, 2014 Private Purchases [Member] Celesio [Member]	Mar. 31, 2014 Private Purchases [Member] The 2014 Bonds [Member] Celesio [Member] convertiblebond	Mar. 31, 2014 Private Purchases [Member] The 2018 Bonds [Member] Celesio [Member] convertiblebond	Mar. 31, 2014 Private Purchases [Member] The 2014 and 2018 Bonds [Member] Celesio [Member] USD ($)	Mar. 31, 2014 Noncontrolling Interest [Member] Celesio [Member] USD ($)	Mar. 31, 2014 Noncontrolling Interest [Member] The 2014 and 2018 Bonds [Member] Celesio [Member]	Mar. 31, 2014 Franz Haniel Cie GmbH [Member] Celesio [Member] USD ($)	Feb. 06, 2014 Franz Haniel Cie GmbH [Member] Celesio [Member]	Apr. 06, 2012 Fair Value, Inputs, Level 2 [Member] Corporate Headquarters [Member] USD ($)	Feb. 06, 2014 Fair Value, Inputs, Level 3 [Member] Celesio [Member] USD ($)	Mar. 31, 2014 Fair Value, Inputs, Level 3 [Member] Celesio [Member] Trademarks [Member] USD ($)	Mar. 31, 2014 Fair Value, Inputs, Level 3 [Member] Celesio [Member] Customer Relationships [Member] USD ($)	Mar. 31, 2014 Fair Value, Inputs, Level 3 [Member] Celesio [Member] Pharmacy Licenses [Member] USD ($)	Feb. 22, 2013 Fair Value, Inputs, Level 3 [Member] PSS World Medical [Member] USD ($)	Feb. 22, 2013 Fair Value, Inputs, Level 3 [Member] PSS World Medical [Member] Customer Relationships [Member] USD ($)	Sep. 30, 2012 Fair Value, Inputs, Level 3 [Member] PSS World Medical [Member] Trademarks and Trade Names [Member] USD ($)	Apr. 06, 2012 Fair Value, Inputs, Level 3 [Member] Corporate Headquarters [Member] USD ($)	Mar. 31, 2012 Fair Value, Inputs, Level 3 [Member] Katz Group [Member] Amounts Recognized As Of Acquisition Date As Adjusted [Member] USD ($)	Mar. 31, 2012 Fair Value, Inputs, Level 3 [Member] Katz Group [Member] Trademarks and Trade Names [Member] Amounts Recognized As Of Acquisition Date As Adjusted [Member] USD ($)	Mar. 31, 2012 Fair Value, Inputs, Level 3 [Member] Katz Group [Member] Service Agreements [Member] Amounts Recognized As Of Acquisition Date As Adjusted [Member] USD ($)	Apr. 22, 2014 Subsequent Event [Member] Celesio [Member]	Mar. 31, 2014 Cost of Sales [Member] USD ($)	Mar. 31, 2014 Cost of Sales [Member] USD ($)	Mar. 31, 2013 Cost of Sales [Member] USD ($)	Mar. 31, 2012 Cost of Sales [Member] USD ($)
Business Acquisition [Line Items]
Effective Date of Acquisition									Feb. 06, 2014					Feb. 22, 2013						Apr. 06, 2012			Mar. 25, 2012
Percentage of Voting Interests Acquired						77.60%	77.60%
Name of Acquired Entity									Celesio AG						PSS World Medical, Inc. (“PSS World Medical”)									Drug Trading Company Limited, the independent banner business of the Katz Group Canada Inc. (“Katz Group”), and Medicine Shoppe Canada Inc., the franchise business of the Katz Group (collectively, “Katz Assets”)
Cash Paid for Acquisition									$ 4,500,000,000					$ 1,300,000,000						$ 90,000,000					$ 925,000,000						$ 951,000,000				$ 63,000,000			$ 4,128,000,000
Subsidiary or Equity Method Investee, Cumulative Percentage Ownership after All Transactions						75.60%	75.60%	75.40%
Business Combination, Consideration Transferred, Liabilities Incurred									2,300,000,000
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						PSS World Medical markets and distributes medical products and services throughout the United States.										The acquisition of the assets from the Drug Trading Company Limited consists of a marketing and purchasing arm of independently owned pharmacies in Canada. The acquisition of Medicine Shoppe Canada Inc. consists of the franchise business of providing services to independent pharmacies in Canada.
Common Shares Acquired																																							129,300,000													1,000,000
Per Share Price of Outstanding Shares Acquired							€ 23.50										$ 29.00
Convertible bonds acquired																											4,840		2,180				303	216
Celesio convertible bonds issued																											7,000		3,500
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles																																									3,018,000,000	172,000,000	1,574,000,000	1,202,000,000	568,000,000	539,000,000	15,000,000		442,000,000	114,000,000	318,000,000
Integration Related Costs	89,000,000			0	0																																																	3,000,000	0	0
Payments To Acquire Business, Convertible Bonds Of Acquiree																												350,000,000		350,000,000
Debt Conversion, Converted Instrument, Shares Issued																													11,400,000		11,900,000	700,000					9,000,000
Conversion of Celesio convertible bonds		313,000,000	313,000,000	0	0
Business Combination Inventory Step-Up Fair Value After-tax Charge																																																					28,000,000
Business Combination, Acquired Bonds Converted																													2,180					139
Business Acquisition Tender Offer Price										€ 23.50
Noncontrolling interests						(1,500,000,000)
Business Combination, Cash Proceeds From Bonds Redeemed																																				30,000,000
Purchase Price for Acquisition														1,900,000,000
Current Portion of Long-Term Debt Acquired																	600,000,000
Weighted average useful life, intangible sssets									17 years		14 years	11 years	26 years		9 years			9 years	2 years						20 years
Previously Held Percentage of Building																					50.00%
Currently Acquired Percentage of Building																					50.00%
Goodwill, Acquired During Period			3,649,000,000	1,421,000,000												1,149,000,000										512,000,000
Gain on business combination			0	81,000,000	0															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
Property, plant and equipment, useful life																						30 years
Goodwill, Expected Tax Deductible Amount																							290,000,000		290,000,000
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual	$ 4,800,000,000