Business Combinations (Fair Value Of Assets Acquired And Liabilities Assumed) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Dec. 31, 2014	Mar. 31, 2014	Feb. 06, 2014
Business Acquisition [Line Items]
Goodwill	$ 9,956	$ 9,927
Measurement period adjustments, goodwill	484
Celesio [Member]
Business Acquisition [Line Items]
Receivables	3,367		3,425	[1]
Measurement period adjustments, receivables	(58)
Other current assets, net of cash and cash equivalents acquired	2,437		2,413	[1]
Measurement period adjustments, other current assets, net of cash and cash equivalents acquired	24
Goodwill	4,054		3,570	[1]
Measurement period adjustments, goodwill	484
Intangible assets	2,482		3,018	[1]
Measurement period adjustment, intangible assets	(536)
Other long-term assets	1,227		1,272	[1]
Measurement period adjustments, other long-term assets	(45)
Current liabilities	(4,099)		(4,096)	[1]
Measurement period adjustments, current liabilities	(3)
Short-term borrowings and current portion of long-term debt	(1,990)		(1,990)	[1]
Measurement period adjustments, short-term borrowings	0
Long-term debt	(322)		(322)	[1]
Measurement period adjustments, , long-term debt	0
Other long-term liabilities	(1,174)		(1,293)	[1]
Measurement period adjustments, other long-term liabilities	119
Fair value of net assets, less cash and cash equivalents	5,982		5,997	[1]
Measurement period adjustments, fair value of net assets	(15)
Less: Noncontrolling Interests	(1,485)		(1,500)	[1]
Measurement period adjustments, less: noncontrolling interest	15
Net assets acquired, less cash and cash equivalents	4,497		4,497	[1]
Measurement period adjustments, net assets acquired	$ 0

[1] (1)As previously reported in our Form 10-K for the year ended March 31, 2014.