Business Combinations (Narrative) (Details) (USD $)	12 Months Ended			1 Months Ended	3 Months Ended		3 Months Ended		3 Months Ended		1 Months Ended	3 Months Ended		3 Months Ended			1 Months Ended	3 Months Ended	6 Months Ended					1 Months Ended	3 Months Ended	9 Months Ended		9 Months Ended		9 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011	Feb. 28, 2013 PSS World Medical [Member]	Mar. 31, 2013 PSS World Medical [Member]	Feb. 22, 2013 PSS World Medical [Member]	Mar. 31, 2013 PSS World Medical [Member] Customer Relationships [Member]	Feb. 22, 2013 PSS World Medical [Member] Customer Relationships [Member]	Mar. 31, 2013 PSS World Medical [Member] Trademarks And Trade Names [Member]	Sep. 30, 2012 PSS World Medical [Member] Trademarks And Trade Names [Member]	Apr. 30, 2013 Corporate Headquarters [Member]	Jun. 30, 2012 Corporate Headquarters [Member]	Apr. 06, 2012 Corporate Headquarters [Member]	Jun. 30, 2012 Corporate Headquarters [Member] Building and Building Improvements [Member]	Apr. 06, 2012 Corporate Headquarters [Member] Building and Building Improvements [Member]	Apr. 06, 2012 Corporate Headquarters [Member] Land [Member]	Mar. 31, 2012 Katz Group [Member]	Sep. 30, 2012 Katz Group [Member]	Sep. 30, 2012 Katz Group [Member]	Sep. 30, 2012 Katz Group [Member] Amounts Recognized As Of Acquisition Date As Adjusted [Member]	Mar. 25, 2012 Katz Group [Member] Amounts Recognized As Of Acquisition Date As Adjusted [Member]	Sep. 30, 2012 Katz Group [Member] Trademarks And Trade Names [Member] Amounts Recognized As Of Acquisition Date As Adjusted [Member]	Sep. 30, 2012 Katz Group [Member] Service Agreements [Member] Amounts Recognized As Of Acquisition Date As Adjusted [Member]	Dec. 31, 2010 US Oncology Holdings Incorporation [Member]	Dec. 31, 2011 US Oncology Holdings Incorporation [Member]	Dec. 31, 2011 US Oncology Holdings Incorporation [Member]	Dec. 31, 2011 US Oncology Holdings Incorporation [Member] Amounts Recognized As Of Acquisition Date As Adjusted [Member]	Dec. 31, 2011 US Oncology Holdings Incorporation [Member] Service Agreements [Member]	Dec. 31, 2011 US Oncology Holdings Incorporation [Member] Service Agreements [Member] Amounts Recognized As Of Acquisition Date As Adjusted [Member]	Dec. 31, 2011 US Oncology Holdings Incorporation [Member] Customer Lists [Member]	Dec. 31, 2011 US Oncology Holdings Incorporation [Member] Customer Lists [Member] Amounts Recognized As Of Acquisition Date As Adjusted [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition				Feb. 22, 2013							Apr. 06, 2012						Mar. 25, 2012							Dec. 30, 2010
Name of Acquired Entity					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”)							US Oncology Holdings, Inc. (“US Oncology”)
Description of Acquired Entity					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.							As an integrated oncology company, US Oncology is affiliated with community-based oncologists, and works with patients, hospitals, payers and the medical industry across all phases of the cancer research and delivery continuum.
Per Share Price of Outstanding Shares Acquired						$ 29.00
Purchase Price for Acquisition						$ 1,900,000,000																					$ 2,100,000,000
Business Acquisition, Purchase Price Allocation, Current Liabilities, Long-term Debt						635,000,000																					1,735,000,000
Liabilities Assumed																											1,900,000,000
Acquired Finite-Lived Intangible Assets						557,000,000		529,000,000		15,000,000										442,000,000		114,000,000	318,000,000				993,000,000		721,000,000		185,000,000
Acquired Finite-Lived Intangible Assets, Weighted Average Useful Life					9 years		9 years		2 years										20 years							16 years		18 years		10 years
Goodwill						1,145,000,000														512,000,000							828,000,000
Goodwill, Expected Tax Deductible Amount																		290,000,000	290,000,000
Currently Acquired Percentage of Building													50.00%
Cash Paid for Acquisition						1,299,000,000							90,000,000							925,000,000	925,000,000						244,000,000
Previously Held Percentage of Building													50.00%
Gain on Business Combination	81,000,000	0	0									81,000,000
Gain on Business Combination, Net of Tax												51,000,000
Fair Value of Assets Acquired													$ 180,000,000		$ 113,000,000	$ 58,000,000
Property, Plant and Equipment, Useful Life														30 years