Debt 4 (Details) - Notional Pooling Arrangement - USD ($) $ in Millions		12 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Notional pooling arrangement
Total borrowings outstanding at beginning of year	[1]	$ 139	$ 138
Borrowings		2,374	3,899
Repayments		(2,351)	(3,877)
Foreign exchange effect		(25)	(21)
Total borrowings outstanding at end of year	[1]	$ 137	$ 139

[1] Included in “Accrued expenses and other current liabilities” in the Company’s Consolidated Balance Sheets.