Financial Instruments - Summarization for Foreign Currency Forward Purchase and Sale Contracts (Details) - Jun. 30, 2017 - Foreign Exchange Forward Contracts € in Millions, £ in Millions, ZAR in Millions, CAD in Millions, $ in Millions	CAD	GBP (£)	USD ($)	ZAR	EUR (€)
British, Pounds | Long
Derivative [Line Items]
Notional Amount in Foreign Currency | £		£ 10
Canada, Dollars | Short
Derivative [Line Items]
Notional Amount in Foreign Currency | CAD	CAD 2
European, Euro | Long
Derivative [Line Items]
Notional Amount in Foreign Currency | €					€ 4
European, Euro | Short
Derivative [Line Items]
Notional Amount in Foreign Currency | €					€ 8
South Africa, Rand | Short
Derivative [Line Items]
Notional Amount in Foreign Currency | ZAR				ZAR 8
U.S., Dollars | Long
Derivative [Line Items]
Notional Amount in Foreign Currency | $			$ 11
U.S., Dollars | Short
Derivative [Line Items]
Notional Amount in Foreign Currency | $			$ 17