CONSOLIDATED COMBINED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Millions	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock	Parent Company Investment
Beginning balance at Oct. 31, 2015	$ 555						$ 555
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	80						80
Transfers to Parent, net	(297)						(297)
Ending balance at Oct. 31, 2016	338						338
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	36						36
Transfers to Parent, net	42						42
Ending balance (in shares) at Mar. 31, 2017		0
Ending balance at Mar. 31, 2017	416	$ 0	$ 0	$ 0	$ 0	$ 0	416
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Effects of purchase accounting	2,434						2,434
Net income	208						208
Transfers to Parent, net	(329)						(329)
Ending balance (in shares) at Mar. 31, 2018		0
Ending balance at Mar. 31, 2018	2,729	$ 0	0	0	0	0	2,729
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Impact of adoption of new accounting standard	4						4
Net income	49						49
Transfers to Parent, net	(145)						(145)
Dividend to DXC prior to May 31, 2018	(984)		(984)
Ending balance (in shares) at May. 31, 2018		0
Ending balance at May. 31, 2018	2,637	$ 0	0	0	0	0	2,637
Beginning balance (in shares) at Mar. 31, 2018		0
Beginning balance at Mar. 31, 2018	2,729	$ 0	0	0	0	0	2,729
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 72
Repurchase of common stock (in shares)	(2,700,000)
Repurchases of common stock	$ (60)
Stock option exercises and other common stock transactions (in shares)	18,000
Ending balance (in shares) at Mar. 31, 2019		165,845,000
Ending balance at Mar. 31, 2019	$ 2,162	$ 2	2,242	2	(23)	(61)	0
Beginning balance (in shares) at May. 31, 2018		0
Beginning balance at May. 31, 2018	2,637	$ 0	0	0	0	0	2,637
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	23			23
Spin-Off activity (in shares)		142,426,000
Spin-Off activity	0	$ 2	2,635				(2,637)
Mergers activity (in shares)		23,273,000
Mergers activity	578		578
Other comprehensive loss	(23)				(23)
Share-based compensation expense	9		9
Repurchase of common stock (in shares)		0
Repurchases of common stock	(60)					(60)
Stock option exercises and other common stock transactions (in shares)		146,000
Stock option exercises and other common stock transactions	1		2			(1)
Dividends declared ($0.20 per common share)	(33)		(12)	(21)
Separation-related tax adjustment	14		14
Ending balance (in shares) at Mar. 31, 2019		165,845,000
Ending balance at Mar. 31, 2019	$ 2,162	$ 2	$ 2,242	$ 2	$ (23)	$ (61)	$ 0