Other Income, Net (Details) - USD ($) $ in Millions	12 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting Information [Line Items]
Interest income	$ 49	$ 39	$ 48
Equity in earnings, net	36	43	32
Estimated net gain on split-off of the Change Healthcare JV	0	56	43
Actuarial losses from pension plans	(127)	0	0
Other, net	54	44	7
Total	12	182	130
Actuarial losses from pension plans	127	$ 0	$ 0
Termination of U.S Defined Benefit Pension Plan \| Pension Plans, Defined Benefit \| United States
Segment Reporting Information [Line Items]
Actuarial losses from pension plans	(116)
Actuarial losses from pension plans	116
Retired executive \| Settlement of Executive Retirement Benefits \| Pension Plans, Defined Benefit \| United States
Segment Reporting Information [Line Items]
Actuarial losses from pension plans	(11)
Actuarial losses from pension plans	$ 11

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