Fair Value Measurements 2 (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013		Mar. 31, 2013
Carrying Value [Member]
Liabilities
Total debt	$ 1,779	[1]	$ 1,290	[1]
Facility exit reserve	32	[2]	23	[2]
Estimated Fair Value [Member]
Liabilities
Total debt	1,892	[1]	1,413	[1]
Facility exit reserve	$ 35	[2]	$ 27	[2]

[1] Estimated fair value of total debt is based on quoted prices for similar liabilities for which significant inputs are observable except for certain long-term lease obligations, for which fair value approximates carrying value (Level 2).

[2] Estimated fair value for the facility exit reserve is determined using the Company’s incremental borrowing rate at September 30, 2013 and March 31, 2013. At September 30, 2013 and March 31, 2013, the facility exit reserve included approximately $10 million and $6 million, respectively, in “Accrued expenses and other current liabilities” and approximately $22 million and $17 million, respectively, in “Other noncurrent liabilities” in the Company’s Condensed Consolidated Balance Sheets (Level 3).