Fair Value Measurements 2 (Details) - USD ($) $ in Millions		Sep. 30, 2015	Mar. 31, 2015	Sep. 30, 2014	Mar. 31, 2014
Liabilities:
Facility exit reserve		$ 24	$ 49	$ 53	$ 84
Facility Exit
Liabilities:
Facility exit reserve		19	21	$ 23	$ 29
Carrying Value
Liabilities:
Total debt	[1]	1,657	1,263
Carrying Value | Facility Exit
Liabilities:
Facility exit reserve	[2]	19	21
Estimated Fair Value
Liabilities:
Total debt	[1]	1,746	1,376
Estimated Fair Value | Facility Exit
Liabilities:
Facility exit reserve	[2]	$ 21	$ 23

[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, 2015 and March 31, 2015. At September 30, 2015 and March 31, 2015, the facility exit reserve included approximately $4 million and $4 million, respectively, in “Accrued expenses and other current liabilities” and approximately $15 million and $17 million, respectively, in “Other noncurrent liabilities” in the Company’s Condensed Consolidated Balance Sheets (Level 3).