Financial Instruments - Summarization for Foreign Currency Forward Purchase and Sale Contracts (Details) - Jun. 30, 2018 - Foreign Exchange Forward Contracts ¥ in Millions, $ in Millions, $ in Millions	CAD ($)	CNY (¥)	USD ($)
Canada, Dollars | Short
Derivative [Line Items]
Notional Amount in Foreign Currency	$ 2
China, Yuan Renminbi | Long
Derivative [Line Items]
Notional Amount in Foreign Currency | ¥		¥ 3
U.S., Dollars | Long
Derivative [Line Items]
Notional Amount in Foreign Currency			$ 2