Financial Instruments - Summarization for Foreign Currency Forward Purchase and Sale Contracts (Details) - Mar. 31, 2017 - Foreign Exchange Forward Contracts € in Millions, ¥ in Millions, £ in Millions, ZAR in Millions, CAD in Millions, $ in Millions	JPY (¥)	CAD	GBP (£)	USD ($)	ZAR	EUR (€)
British, Pounds | Long
Derivative [Line Items]
Notional Amount in Foreign Currency | £			£ 19
British, Pounds | Short
Derivative [Line Items]
Notional Amount in Foreign Currency | £			£ 9
Canada, Dollars | Long
Derivative [Line Items]
Notional Amount in Foreign Currency | CAD		CAD 2
Canada, Dollars | Short
Derivative [Line Items]
Notional Amount in Foreign Currency | CAD		CAD 4
European, Euro | Long
Derivative [Line Items]
Notional Amount in Foreign Currency | €						€ 10
European, Euro | Short
Derivative [Line Items]
Notional Amount in Foreign Currency | €						€ 5
Japan, Yen | Long
Derivative [Line Items]
Notional Amount in Foreign Currency | ¥	¥ 89
Japan, Yen | Short
Derivative [Line Items]
Notional Amount in Foreign Currency | ¥	¥ 90
South Africa, Rand | Short
Derivative [Line Items]
Notional Amount in Foreign Currency | ZAR					ZAR 7
U.S., Dollars | Long
Derivative [Line Items]
Notional Amount in Foreign Currency | $				$ 21
U.S., Dollars | Short
Derivative [Line Items]
Notional Amount in Foreign Currency | $				$ 35