Commitments and Contingencies Personal Injury (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Unasserted Claim
Asbestos and Personal Injury [Abstract]
Percent of future unasserted asbestos claims to be filed within the next ten years	65.00%
Percent of future unasserted asbestos claims to be filed within the next fifteen years	80.00%
Percent of future unasserted asbestos claims to be filed within the next twenty-five years	95.00%
Length in years for 65 percent of future unasserted asbestos claims to be filed	10 years
Length in years for 80 percent of future unasserted asbestos claims to be filed	15 years
Length in years for 95 percent of future unasserted asbestos claims to be filed	25 years
Personal Injury [Member]
Asbestos and Personal Injury [Abstract]
Loss Contingency, Accrual, Current	$ 85		$ 85
Loss Contingency Accrual [Roll Forward]
Beginning balance	307	$ 367
Accruals / changes in estimates	7	14
Payments	(9)	(14)
Ending balance	305	$ 367
Loss Contingency, Accrual, Current	85		$ 85
Personal Injury [Member] | Minimum [Member]
Asbestos and Personal Injury [Abstract]
Future costs to settle claims and associated liability	260
Personal Injury [Member] | Maximum [Member]
Asbestos and Personal Injury [Abstract]
Future costs to settle claims and associated liability	$ 360