Restructuring and Other Charges - Narrative (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($) employee	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges	$ 5	$ 105	$ 14	$ 144
Settlements	3	$ 64	6	64
Reversal of impairment charge due to reclassification of assets | employee		7,000,000
Gain (loss) on sale of assets			3
Pension benefits
Restructuring Cost and Reserve [Line Items]
Settlements	$ 3	$ 64	$ 6	64
Layoff costs for the separation
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges		54		76
U.S. Pension Plan Settlement Accounting
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges				6
Other exit costs
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges		2		5
Reversal of prior period programs
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges		8		10
U.K. Pension Plan Settlement Accounting
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges		$ 64		64
Impairment of Property, Plant and Equipment
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges				5
Sale of Assets
Restructuring Cost and Reserve [Line Items]
Gain (loss) on sale of assets				$ 2