Fair Value Measurements 3 (Details) - USD ($) $ in Millions	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Facility exit reserve	$ 12	$ 19	$ 49	$ 84
Facility Exit
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Facility exit reserve	11	16	$ 21	$ 29
Facility Exit | Accrued Expenses and Other Current Liabilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Facility exit reserve	3	4
Facility Exit | Other Noncurrent Liabilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Facility exit reserve	$ 8	$ 12