Revenue from Contracts with Customers - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Net sales	$ 1,026	$ 1,009	$ 2,091	$ 1,950
North America
Disaggregation of Revenue [Line Items]
Net sales	602	552	1,152	1,049
Europe
Disaggregation of Revenue [Line Items]
Net sales	342	370	764	731
APAC & Emerging Markets
Disaggregation of Revenue [Line Items]
Net sales	85	90	180	176
Operating Segments | North America
Disaggregation of Revenue [Line Items]
Net sales	602	552	1,152	1,049
Operating Segments | Europe
Disaggregation of Revenue [Line Items]
Net sales	342	370	764	731
Operating Segments | APAC & Emerging Markets
Disaggregation of Revenue [Line Items]
Net sales	85	90	180	176
Operating Segments | Supply Chain Services
Disaggregation of Revenue [Line Items]
Net sales	917	927	1,893	1,814
Operating Segments | Supply Chain Services | North America
Disaggregation of Revenue [Line Items]
Net sales	495	472	956	915
Operating Segments | Supply Chain Services | Europe
Disaggregation of Revenue [Line Items]
Net sales	342	370	766	733
Operating Segments | Supply Chain Services | APAC & Emerging Markets
Disaggregation of Revenue [Line Items]
Net sales	83	88	176	172
Operating Segments | Software Solutions
Disaggregation of Revenue [Line Items]
Net sales	23	25	48	51
Operating Segments | Software Solutions | North America
Disaggregation of Revenue [Line Items]
Net sales	19	20	40	42
Operating Segments | Software Solutions | Europe
Disaggregation of Revenue [Line Items]
Net sales	2	3	4	5
Operating Segments | Software Solutions | APAC & Emerging Markets
Disaggregation of Revenue [Line Items]
Net sales	2	2	4	4
Operating Segments | Prescription Management
Disaggregation of Revenue [Line Items]
Net sales	110	67	195	100
Operating Segments | Prescription Management | North America
Disaggregation of Revenue [Line Items]
Net sales	110	67	195	100
Operating Segments | Prescription Management | Europe
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Operating Segments | Prescription Management | APAC & Emerging Markets
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Eliminations
Disaggregation of Revenue [Line Items]
Net sales	(24)	(10)	(45)	(15)
Eliminations | North America
Disaggregation of Revenue [Line Items]
Net sales	(22)	(7)	(39)	(8)
Eliminations | Europe
Disaggregation of Revenue [Line Items]
Net sales	(2)	(3)	(6)	(7)
Eliminations | APAC & Emerging Markets
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Eliminations
Disaggregation of Revenue [Line Items]
Net sales	(3)	(3)	(5)	(6)
Eliminations | Supply Chain Services
Disaggregation of Revenue [Line Items]
Net sales	(3)	(3)	(5)	(6)
Eliminations | Software Solutions
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Eliminations | Prescription Management
Disaggregation of Revenue [Line Items]
Net sales	$ 0	$ 0	$ 0	$ 0