Restructuring and other (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Restructuring Cost and Reserve [Line Items]
Restructuring and other	$ 20	$ 11	$ 58	$ 24
Employee severance
Restructuring Cost and Reserve [Line Items]
Restructuring and other	9	3	39	8
Employee severance | Contingencies Related to COVID-19 [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other	7		31
Contingent Consideration Adjustment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other	0	0	0	2
Restructuring, integration and other
Restructuring Cost and Reserve [Line Items]
Restructuring and other	$ 11	$ 8	$ 19	$ 14