Recent Accounting Pronouncements Pension Restatement ASU Adoption (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of Goods and Services Sold	$ (1,323)	$ (1,145)	$ (2,659)	$ (2,266)
Selling, General and Administrative Expense	(136)	(117)	(283)	(220)
Other (charges) gains, net	(3)	(2)	(3)	(57)
Operating Income (Loss)	358	218	701	388
Non-operating pension and other postretirement employee benefit (expense) income	$ 26	22	$ 52	44
Scenario, Previously Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of Goods and Services Sold		(1,143)		(2,262)
Selling, General and Administrative Expense		(96)		(179)
Other (charges) gains, net		(3)		(58)
Operating Income (Loss)		240		432
Non-operating pension and other postretirement employee benefit (expense) income		0		0
Restatement Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of Goods and Services Sold		2		4
Selling, General and Administrative Expense		21		41
Other (charges) gains, net		(1)		(1)
Operating Income (Loss)		(22)		(44)
Non-operating pension and other postretirement employee benefit (expense) income		$ 22		$ 44