Business Acquisition - Restructuring (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2016	Sep. 30, 2015
Restructuring Cost and Reserve [Line Items]
Expected costs	$ 7	$ 7
Restructuring reserve	3	3
Medsystems Holdings, Inc.
Restructuring Cost and Reserve [Line Items]
Restructuring charges	3	10
Medsystems Holdings, Inc. | Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1		$ 4
Payments for restructuring	$ 1	$ 1