Debt 4 (Details) - Notional Pooling Arrangement - USD ($) $ in Millions		12 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Notional pooling arrangement
Borrowings		$ 2,310	$ 2,374
Repayments		(2,354)	(2,351)
Foreign exchange effect		44	(25)
Accrued Expenses and Other Current Liabilities
Notional pooling arrangement
Total borrowings outstanding at beginning of year	[1]	137	139
Total borrowings outstanding at end of year	[1]	$ 137	$ 137

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