Pensions and Other Postretirement Benefits (Additional Information) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected future employer contributions, excluding settlment losses	$ 25
Pension settlement charges, pre tax	0	$ 22
Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected future employer contributions, excluding settlment losses	35
Pension settlement charges, pre tax	0
Other Postretirement Benefits Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected future employer contributions, excluding settlment losses	10
Pension settlement charges, pre tax	0	0
U.S. Non-qualified Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Cash payment to retirees - U.S. Non-qualified Pension Plan		40
UNITED STATES
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions to defined benefit pension plans	25	29
Foreign Plan | Minimum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected employer mandatory contributions	20
Foreign Plan | Maximum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected employer mandatory contributions	30
Foreign Plan | Mandatory Contribution
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions to defined benefit pension plans	$ 5	5
U.S. Non-qualified Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension settlement charges, pre tax		22
Noncash Pension Settlement Charge - after tax		$ 14