Stockholders' Equity - Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
AOCI Including Portion Attributable to Noncontrolling Interest [Abstract]
Beginning balance	$ 5,129	$ 11,725
Current-period other comprehensive income (loss)	203	76
Amounts reclassified from accumulated other comprehensive loss	(7)	(8)
Ending balance	5,995	9,101
Foreign Currency Translation Adjustments
AOCI Including Portion Attributable to Noncontrolling Interest [Abstract]
Beginning balance	(851)	(517)
Current-period other comprehensive income (loss)	197	78
Amounts reclassified from accumulated other comprehensive loss	0	0
Ending balance	(654)	(439)
Cash Flow Hedges
AOCI Including Portion Attributable to Noncontrolling Interest [Abstract]
Beginning balance	(20)	(3)
Current-period other comprehensive income (loss)	12	(4)
Amounts reclassified from accumulated other comprehensive loss	6	(2)
Ending balance	(2)	(9)
Available-for-sale Securities
AOCI Including Portion Attributable to Noncontrolling Interest [Abstract]
Beginning balance	9	9
Current-period other comprehensive income (loss)	(6)	2
Amounts reclassified from accumulated other comprehensive loss	0	0
Ending balance	3	11
Pension and Other Post-retirement Benefit Plans
AOCI Including Portion Attributable to Noncontrolling Interest [Abstract]
Beginning balance	259	267
Current-period other comprehensive income (loss)	0	0
Amounts reclassified from accumulated other comprehensive loss	(13)	(6)
Ending balance	246	261
Accumulated Other Comprehensive Loss
AOCI Including Portion Attributable to Noncontrolling Interest [Abstract]
Beginning balance	(603)	(244)
Ending balance	$ (407)	$ (176)