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Debt 1 (Details) - USD ($) $ in Millions	Mar. 31, 2018	Mar. 31, 2017	Aug. 16, 2013
Debt obligations
Other indebtedness, primarily capital leases	$ 10	$ 8
Unamortized debt issuance costs	(11)	(14)
Unamortized discount for Senior Notes	(1)	(3)
Total debt outstanding	2,783	2,791
Less the current portion	(269)	(18)
Total long-term debt portion	2,514	2,773
Revolving Credit Facility
Debt obligations
Long-term debt	0	0
2.875% Senior Notes due August 2018
Debt obligations
Long-term debt	250	250
Unamortized discount for Senior Notes			$ (1)
5.375% Senior Notes due December 2019
Debt obligations
Long-term debt	750	750
3.600% Senior Notes due August 2020
Debt obligations
Long-term debt	400	400
3.600% Senior Notes due August 2022
Debt obligations
Long-term debt	500	500
4.500% Senior Notes due August 2023
Debt obligations
Long-term debt	250	250
Unamortized discount for Senior Notes			$ (1)
4.700% Senior Notes due March 2027
Debt obligations
Long-term debt	350	350
Term Loan due April 2023
Debt obligations
Long-term debt	$ 285	$ 300