Stockholders' Equity - Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	9 Months Ended
	Dec. 31, 2017		Dec. 30, 2016
AOCI Including Portion Attributable to Noncontrolling Interest [Abstract]
Balance, beginning	$ 2,166	[1]	$ 2,032
Balance, ending	13,202		2,194
Foreign Currency Translation Adjustments
AOCI Including Portion Attributable to Noncontrolling Interest [Abstract]
Balance, beginning	(458)		(399)
Current-period other comprehensive income	62		(180)
Amounts reclassified from accumulated other comprehensive income	8		0
Balance, ending	(404)		(579)
Cash Flow Hedges
AOCI Including Portion Attributable to Noncontrolling Interest [Abstract]
Balance, beginning	20		(1)
Current-period other comprehensive income	0		15
Amounts reclassified from accumulated other comprehensive income	0		0
Balance, ending	20		14
Pension and Other Post-retirement Benefit Plans
AOCI Including Portion Attributable to Noncontrolling Interest [Abstract]
Balance, beginning	276		289
Current-period other comprehensive income	0		0
Amounts reclassified from accumulated other comprehensive income	10		(10)
Balance, ending	266		279
Accumulated Other Comprehensive (Loss) Income
AOCI Including Portion Attributable to Noncontrolling Interest [Abstract]
Balance, beginning	(162)		(111)
Current-period other comprehensive income	62		(165)
Amounts reclassified from accumulated other comprehensive income	18		(10)
Balance, ending	$ (118)		$ (286)

[1] Certain prior year amounts were adjusted to retroactively reflect the legal capital of DXC.