Fair Value Measurements 1 (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Millions		Mar. 31, 2017	Mar. 31, 2016
Assets:
Foreign exchange derivatives	[1]	$ 2	$ 2
Total assets		1,079	822
Liabilities:
Foreign exchange derivatives	[1]	1	3
Total liabilities		1	3
Money Market Funds | Cash and Cash Equivalents
Assets:
Money market funds	[2]	1,077	820
Fair Value, Inputs, Level 1
Assets:
Foreign exchange derivatives		0	0
Total assets		1,077	820
Liabilities:
Foreign exchange derivatives		0	0
Total liabilities		0	0
Fair Value, Inputs, Level 1 | Money Market Funds | Cash and Cash Equivalents
Assets:
Money market funds	[2]	1,077	820
Fair Value, Inputs, Level 2
Assets:
Foreign exchange derivatives	[1]	2	2
Total assets		2	2
Liabilities:
Foreign exchange derivatives	[1]	1	3
Total liabilities		1	3
Fair Value, Inputs, Level 2 | Money Market Funds | Cash and Cash Equivalents
Assets:
Money market funds		0	0
Fair Value, Inputs, Level 3
Assets:
Total assets		0	0
Liabilities:
Total liabilities		$ 0	$ 0

[1] Refer to Note 9, “Derivatives” for additional information.

[2] The Company’s investments in money market funds are classified as “Cash and cash equivalents” in its Consolidated Balance Sheets.