Amount of gain (loss) on sale or disposal of an equity method investment.

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Other Income, Net (Details) - USD ($) $ in Millions	3 Months Ended					12 Months Ended
Other Income, Net (Details) - USD ($) $ in Millions	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Interest income						$ 39	$ 48	$ 29
Equity in earnings, net		$ 23	$ (90)	$ (61)	$ (120)
Gain from sale of equity method investment, pre-tax								0
Other, net						44	7	18
Total						182	130	77
European Pharmaceutical Solutions
Segment Reporting Information [Line Items]
Equity in earnings, net						43	32	$ 30
Other
Segment Reporting Information [Line Items]
Gain from sale of equity method investment, pre-tax	$ 56					$ 56
U.S. Pharmaceutical and Specialty Solutions
Segment Reporting Information [Line Items]
Gain from sale of equity method investment, pre-tax							$ 43