Share-Based Payments - Components of Share-Based Compensation Expense (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense—direct	$ 16	$ 17	$ 32	$ 35
Stock options / stock appreciation rights
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense—direct	2	2	5	5
RSUs / DSUs(a)(b)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense—direct	9	12	17	24
PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense—direct	$ 5	3	$ 10	6
Abaxis Inc
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense—direct		4		9
Share-based Payment Arrangement, Accelerated Cost		$ 2		$ 4