Business Combinations (Fair Value Of Assets Acquired And Liabilities Assumed) (Details) (US Oncology Holdings, Inc. [Member], USD $) In Millions, unless otherwise specified	Dec. 30, 2010 Amounts Previously Recognized As Of Acquisition Date (Provisional) [Member]		Dec. 31, 2011 Measurement Period Adjustments [Member]	Dec. 31, 2011 Amounts Recognized As Of Acquisition Date (Final) [Member]
Business Acquisition [Line Items]
Current assets, net of cash acquired	$ 662	[1]	$ (13)	$ 649
Goodwill	808	[1]	20	828
Intangible assets	1,007	[1]	(14)	993
Other long-term assets	354	[1]	(6)	348
Current liabilities	(489)	[1]	(1)	(490)
Current portion of long-term debt	(1,735)	[1]	0	(1,735)
Other long-term liabilities	(338)	[1]	16	(322)
Other stockholders' equity	(25)	[1]	(2)	(27)
Net assets acquired, less cash and cash equivalents	$ 244	[1]	$ 0	$ 244

[1] As previously reported in our Form 10-K for the year ended March 31, 2011.