Pension and Postretirement Benefit Plans - Reconciliation of Level 3 Pension Plan Assets (Details) - Pension Plan [Member] - USD ($)		12 Months Ended
		Dec. 31, 2019		Dec. 31, 2018
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Fair value at beginning of period		$ 1,372,000,000
Fair value at end of period		802,000,000		$ 1,372,000,000
Insurance Contracts [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Fair value at beginning of period	[1]	35,000,000
Fair value at end of period	[1]	50,000,000		35,000,000
Foreign Plan [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Fair value at beginning of period		71,000,000		71,000,000
Fair value at end of period		78,000,000		71,000,000
Foreign Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Fair value at beginning of period		35,000,000
Fair value at end of period		46,000,000		35,000,000
Foreign Plan [Member] | Insurance Contracts [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Actual gains relating to assets still held at the reporting date		7,000,000		4,000,000
Purchases, sales and settlements		5,000,000		(1,000,000)
Currency impact		(1,000,000)		(1,000,000)
Foreign Plan [Member] | Insurance Contracts [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Fair value at beginning of period		35,000,000	[1]	33,000,000
Fair value at end of period	[1]	46,000,000		35,000,000
UNITED STATES
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Fair value at beginning of period		1,301,000,000		1,513,000,000
Fair value at end of period		724,000,000		1,301,000,000
UNITED STATES | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Fair value at end of period		4,000,000
UNITED STATES | Insurance Contracts [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Purchases, sales and settlements		4,000,000
UNITED STATES | Insurance Contracts [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Fair value at beginning of period		0
Fair value at end of period		$ 4,000,000	[1]	$ 0

[1] This category comprises contracts placed with insurance companies where the underlying assets are invested in fixed interest securities.