CONDENSED CONSOLIDATED COMBINED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (unaudited) - USD ($) $ in Millions	Total	Common Stock	Additional Paid-in Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Parent Company Investment
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 (loss)	49						49
Transfers to Parent, net	(145)						(145)
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 (loss)	53
Stock-based compensation	3
Dividends declared	(16)
Ending balance (in shares) at Sep. 30, 2018		164,819,000
Ending balance at Sep. 30, 2018	2,203	$ 2	2,219	0	5	(23)	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 (loss)	(20)			(20)
Dividend to DXC prior to May 31, 2018	(984)		(984)
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 income (loss)	(1)				(1)
Dividends declared	(8)		(8)
Ending balance (in shares) at Jun. 30, 2018		165,699,000
Ending balance at Jun. 30, 2018	2,202	$ 2	2,221	(20)	(1)	0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	24			24
Other comprehensive income (loss)	6				6
Stock-based compensation	1		1
Repurchases of common stock (in shares)		(923,000)
Repurchases of common stock	(23)					(23)
Stock option exercises and other common stock transactions (in shares)		43,000
Stock option exercises and other common stock transactions	1		1
Dividends declared	(8)		(4)	(4)
Ending balance (in shares) at Sep. 30, 2018		164,819,000
Ending balance at Sep. 30, 2018	2,203	$ 2	2,219	0	5	(23)	$ 0
Beginning balance (in shares) at Mar. 31, 2019		165,845,000
Beginning balance at Mar. 31, 2019	2,162	$ 2	2,242	2	(23)	(61)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	31			31
Other comprehensive income (loss)	(18)				(18)
Stock-based compensation	5		5
Repurchases of common stock	(15)					(15)
Stock option exercises and other common stock transactions (in shares)		42,000
Dividends declared	(10)			(10)
Ending balance (in shares) at Jun. 30, 2019		165,887,000
Ending balance at Jun. 30, 2019	2,155	$ 2	2,247	23	(41)	(76)
Beginning balance (in shares) at Mar. 31, 2019		165,845,000
Beginning balance at Mar. 31, 2019	2,162	$ 2	2,242	2	(23)	(61)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	60
Stock-based compensation	$ 15
Repurchases of common stock (in shares)	(1,357,859)
Dividends declared	$ (20)
Ending balance (in shares) at Sep. 30, 2019		165,987,000
Ending balance at Sep. 30, 2019	2,163	$ 2	2,257	42	(44)	(94)
Beginning balance (in shares) at Jun. 30, 2019		165,887,000
Beginning balance at Jun. 30, 2019	2,155	$ 2	2,247	23	(41)	(76)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	29			29
Other comprehensive income (loss)	(3)				(3)
Stock-based compensation	10		10
Repurchases of common stock	(17)					(17)
Stock option exercises and other common stock transactions (in shares)		100,000
Stock option exercises and other common stock transactions	(1)					(1)
Dividends declared	(10)			(10)
Ending balance (in shares) at Sep. 30, 2019		165,987,000
Ending balance at Sep. 30, 2019	$ 2,163	$ 2	$ 2,257	$ 42	$ (44)	$ (94)