Fair Value Measurements (Fair Value Measurements Using Significant Unobservable Inputs (Level 3)) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Mar. 31, 2014		Mar. 31, 2013		Mar. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payments	$ (1)		$ (28)		$ (25)
Significant Unobservable Inputs (Level 3) [Member] | Contingent Consideration [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Beginning Balance	43		112
Change in fair value	(35)	[1]	(64)	[1]
Payments	4	[2]	5	[2]
Ending Balance	$ 4		$ 43

[1] The change in fair value is reported as acquisition-related contingent consideration in our Consolidated Statements of Operations.

[2] During fiscal year 2014, we made payments totaling $4 million to settle certain performance milestones achieved in connection with one of our acquisitions. During fiscal year 2013, we made payments totaling $5 million to settle certain performance milestones achieved in connection with two of our acquisitions.