Property, Plant, and Equipment (Narative) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2017 USD ($) item
Property, Plant And Equipment [Abstract]
Sale Leaseback Transaction, Gross Proceeds, Investing Activities	$ 86
Sale Leaseback Transaction, Deferred Gain, Net	59
Sale Leaseback Transaction, Deferred Gain, Current	26
Sale Leaseback Transaction, Deferred Gain, Long Term	$ 33
Sale Leaseback Transaction, Deferred Gain, Amortization Period | item	2