Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended			9 Months Ended
	Dec. 30, 2016	Jan. 01, 2016		Dec. 30, 2016	Jan. 01, 2016
Net income attributable to CSC common stockholders
From continuing operations	$ 31	$ 22		$ 25	$ 179
From discontinued operations	0	28		0	205
Net income attributable to CSC common stockholders	$ 31	$ 50	[1]	$ 25	$ 384	[1]
Common share information:
Weighted average common shares outstanding for basic EPS (in shares)	140,880,000	138,860,000		140,130,000	138,360,000
Dilutive effect of stock options and equity awards (in shares)	3,930,000	2,710,000		3,670,000	3,030,000
Weighted average common shares outstanding for diluted EPS (in shares)	144,810,000	141,570,000		143,800,000	141,390,000
Basic EPS:
Continuing operations (in dollars per share)	$ 0.22	$ 0.16	[1]	$ 0.18	$ 1.29	[1]
Discontinued operations (in dollars per share)	0.00	0.20	[1]	0.00	1.49	[1]
Earnings per common share - basic (in dollars per share)	0.22	0.36	[1]	0.18	2.78	[1]
Diluted EPS:
Continuing operations (in dollars per share)	0.21	0.15	[1]	0.17	1.27	[1]
Discontinued operations (in dollars per share)	0.00	0.20	[1]	0.00	1.45	[1]
Earnings per common share - diluted (in dollars per share)	$ 0.21	$ 0.35	[1]	$ 0.17	$ 2.72	[1]
Weighted average common shares outstanding for diluted EPS (in shares)	144,810,000	141,570,000		143,800,000	141,390,000
Antidilution Due To Exercise Price Exceeding Average Market Price | Employee stock option
Antidilutive securities excluded from computation (in shares)		2,953,605		1,621,950	1,986,904
Antidilution Due To Exercise Price Exceeding Average Market Price | Performance stock units
Antidilutive securities excluded from computation (in shares)	1,956,698
Antidilution Due To Exercise Price Exceeding Average Market Price | Restricted Stock Units (RSUs)
Antidilutive securities excluded from computation (in shares)	1,470	273,989		1,611	222,862
New accounting pronouncement, early adoption, effect
Common share information:
Weighted average common shares outstanding for diluted EPS (in shares)		141,570,000			141,390,000
Weighted average common shares outstanding for diluted EPS (in shares)		141,570,000			141,390,000
New accounting pronouncement, early adoption, calculation under previous guidance
Common share information:
Weighted average common shares outstanding for diluted EPS (in shares)		141,180,000			141,000,000
Weighted average common shares outstanding for diluted EPS (in shares)		141,180,000			141,000,000

[1] Certain prior year balances were adjusted for certain errors in previously issued financial statements related to income taxes and for the adoption of ASU 2016-09 related to employee stock-based compensation. See Note 20 - Reconciliation of Previously Reported Amounts.