Income Taxes (Details) - USD ($)	3 Months Ended			6 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Segment Reporting Information [Line Items]
Income tax expense related to continuing operations	$ 35,000,000		$ 122,000,000	$ 122,000,000	$ 217,000,000
Goodwill impairment, tax benefit				0	0
Goodwill and asset impairment charges	0	$ 570,000,000	$ 350,000,000	570,000,000	$ 350,000,000
Provisional tax benefit due to re-measurement of deferred taxes				(1,324,000,000)
Provisional tax expense for the one-time tax				442,000,000
Discrete tax benefit related to accumulated earnings and profits	15,000,000
Unrecognized tax benefits	991,000,000			991,000,000
Unrecognized tax benefits that would reduce income tax expense and the effective tax rate	828,000,000			828,000,000
Decrease in unrecognized tax benefit	171,000,000
Increase in taxes payable	171,000,000
Discrete tax benefit recognized	42,000,000
Discrete tax benefit for reduction in provisional amount of unrecognized tax benefits	$ 23,000,000
U.S. Pharmaceutical and Specialty Solutions
Segment Reporting Information [Line Items]
Goodwill and asset impairment charges				$ 0