Company Restructuring - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges	$ 71	$ 13	$ 122	$ 17
Employee costs
Restructuring Cost and Reserve [Line Items]
Cumulative amount incurred to date for active programs	249		249
Exit costs
Restructuring Cost and Reserve [Line Items]
Cumulative amount incurred to date for active programs	147		147
Transformative Growth
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges			1		$ (238)
Decrease in expected costs	40		40
Future work environment
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges			(79)		$ 0
Decrease in expected costs	$ 0		$ 0