Share-Based Payments - Components of Share-Based Compensation Expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019		Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense—direct	$ 16	$ 14	$ 51	[1]	$ 36	[1]
Share-based Payment Arrangement, Accelerated Cost	1		5
Stock options / stock appreciation rights
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense—direct	3	2	8		7
RSUs / DSUs(a)(b)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense—direct	10	10	34	[2]	23	[2]
PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense—direct	3	$ 2	9		$ 6
Abaxis Inc
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense—direct	$ 4		$ 13

[1] mounts capitalized to inventory were $1 million for the nine months ended September 30, 2019 and were insignificant for the three months ended September 30, 2019 as well as for the three and nine months ended September 30, 2018.

[2] For the three and nine months ended September 30, 2019, includes share-based compensation expense of $4 million and $13 million, respectively, related to the acquisition of Abaxis for the post-merger service period. For additional details, see Note 5. Acquisitions.