Recent Accounting Pronouncements Pension Restatement ASU Adoption (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of Goods and Services Sold	$ (1,255)	$ (1,183)	$ (3,914)	$ (3,449)
Selling, General and Administrative Expense	(129)	(133)	(412)	(353)
Other (charges) gains, net	12	0	9	(57)
Operating Income (Loss)	374	229	1,075	617
Non-operating pension and other postretirement employee benefit (expense) income	$ 25	23	$ 77	67
Accounting Standards Update 2017-07 [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of Goods and Services Sold		2		6
Selling, General and Administrative Expense		21		62
Other (charges) gains, net				(1)
Operating Income (Loss)		(23)		(67)
Non-operating pension and other postretirement employee benefit (expense) income		23		67
Previously Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of Goods and Services Sold		(1,181)		(3,443)
Selling, General and Administrative Expense		(112)		(291)
Other (charges) gains, net				(58)
Operating Income (Loss)		252		684
Non-operating pension and other postretirement employee benefit (expense) income		$ 0		$ 0