Financial Instruments - Summarization for Foreign Currency Forward Purchase and Sale Contracts (Details) - Mar. 31, 2016 - Foreign Exchange Forward Contracts € in Millions, ¥ in Millions, £ in Millions, ZAR in Millions, CAD in Millions, AUD in Millions, $ in Millions	CAD	GBP (£)	EUR (€)	JPY (¥)	ZAR	AUD	USD ($)
Australia, Dollars | Long
Derivative [Line Items]
Purchase (Sell) Notional Amount in Foreign Currency | AUD						AUD 1
British, Pounds | Long
Derivative [Line Items]
Purchase (Sell) Notional Amount in Foreign Currency | £		£ 39
British, Pounds | Short
Derivative [Line Items]
Purchase (Sell) Notional Amount in Foreign Currency | £		£ (39)
Canada, Dollars | Short
Derivative [Line Items]
Purchase (Sell) Notional Amount in Foreign Currency | CAD	CAD (2)
European, Euro | Long
Derivative [Line Items]
Purchase (Sell) Notional Amount in Foreign Currency | €			€ 19
European, Euro | Short
Derivative [Line Items]
Purchase (Sell) Notional Amount in Foreign Currency | €			€ (41)
South Africa, Rand | Long
Derivative [Line Items]
Purchase (Sell) Notional Amount in Foreign Currency | ZAR					ZAR 70
South Africa, Rand | Short
Derivative [Line Items]
Purchase (Sell) Notional Amount in Foreign Currency | ZAR					ZAR (200)
Japan, Yen | Long
Derivative [Line Items]
Purchase (Sell) Notional Amount in Foreign Currency | ¥				¥ 400
Japan, Yen | Short
Derivative [Line Items]
Purchase (Sell) Notional Amount in Foreign Currency | ¥				¥ (416)
U.S., Dollars | Long
Derivative [Line Items]
Purchase (Sell) Notional Amount in Foreign Currency | $							$ 105
U.S., Dollars | Short
Derivative [Line Items]
Purchase (Sell) Notional Amount in Foreign Currency | $							$ (70)