Pension and Postretirement Benefit Plans - Fair Value of Pension Plan Assets (Details) - Pension Plan [Member] - USD ($)		Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		$ 802,000,000		$ 1,372,000,000
UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		724,000,000		1,301,000,000		$ 1,513,000,000
Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		78,000,000		71,000,000		71,000,000
Fair Value, Inputs, Level 1 [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		39,000,000		39,000,000
Fair Value, Inputs, Level 1 [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0		0
Fair Value, Inputs, Level 2 [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		288,000,000		883,000,000
Fair Value, Inputs, Level 2 [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		32,000,000		36,000,000
Fair Value, Inputs, Level 3 [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		4,000,000
Fair Value, Inputs, Level 3 [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		46,000,000		35,000,000
Fair Value Measured at Net Asset Value Per Share [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	393,000,000		379,000,000
Defined Benefit Plan, Equity Securities, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[2]	39,000,000		35,000,000
Defined Benefit Plan, Equity Securities, US [Member] | Fair Value, Inputs, Level 1 [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[2]	39,000,000		35,000,000
Defined Benefit Plan, Equity Securities, US, Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		28,000,000		43,000,000
Defined Benefit Plan, Equity Securities, US, Large Cap [Member] | Fair Value Measured at Net Asset Value Per Share [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	28,000,000		43,000,000
Defined Benefit Plan, Equity Securities, US, Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets				4,000,000
Defined Benefit Plan, Equity Securities, US, Small Cap [Member] | Fair Value, Inputs, Level 1 [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets				4,000,000
Defined Benefit Plan, Equity Securities, Non-US [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		19,000,000		41,000,000
Defined Benefit Plan, Equity Securities, Non-US [Member] | Fair Value Measured at Net Asset Value Per Share [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	19,000,000		41,000,000
Defined Benefit Plan, Equity Securities, Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		9,000,000		28,000,000
Defined Benefit Plan, Equity Securities, Emerging Markets [Member] | Fair Value Measured at Net Asset Value Per Share [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	9,000,000		28,000,000
Defined Benefit Plan, Debt Security [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[3]			33,000,000
Defined Benefit Plan, Debt Security [Member] | Fair Value, Inputs, Level 2 [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[3]			33,000,000
Defined Benefit Plan, Debt Security [Member] | Fair Value Measured at Net Asset Value Per Share [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1],[3]
Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		492,000,000		814,000,000
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		186,000,000		616,000,000
Corporate Debt Securities [Member] | Fair Value Measured at Net Asset Value Per Share [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	306,000,000		198,000,000
US Treasury Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		37,000,000		115,000,000
US Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		37,000,000		115,000,000
Debt Security, Government, Non-US [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		21,000,000		25,000,000
Debt Security, Government, Non-US [Member] | Fair Value, Inputs, Level 2 [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		21,000,000		25,000,000
Defined Benefit Plan, Fixed Income Securities, Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		11,000,000		48,000,000
Defined Benefit Plan, Fixed Income Securities, Emerging Markets [Member] | Fair Value Measured at Net Asset Value Per Share [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	11,000,000		48,000,000
Insurance Contracts [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[4]	50,000,000		35,000,000
Insurance Contracts [Member] | Fair Value, Inputs, Level 3 [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		4,000,000	[4]	0
Insurance Contracts [Member] | Fair Value, Inputs, Level 3 [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		46,000,000	[4]	35,000,000	[4]	$ 33,000,000
Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		20,000,000		21,000,000
Real Estate [Member] | Fair Value Measured at Net Asset Value Per Share [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	20,000,000		21,000,000
Other Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		11,000,000		10,000,000
Other Securities [Member] | Fair Value, Inputs, Level 2 [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Other Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		11,000,000		10,000,000
Other Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		65,000,000		120,000,000
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		65,000,000		119,000,000
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets				$ 1,000,000

[1] Certain assets are measured at fair value using the net asset value (NAV) per share (or its equivalent) practical expedient and have not been classified in the fair value hierarchy.

[2] This category comprises a combination of small-, mid- and large-cap equity stocks that are allocated at the investment manager's discretion. Investments include common and preferred securities as well as equity funds that invest in these instruments.

[3] This category represents a combination of high-yield and investment grade corporate bonds, sovereign bonds, Yankee bonds, asset-backed securities and U.S. government bonds. Investments include fixed income funds that invest in these instruments.

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