Sale of Receivables (Details) - USD ($)	3 Months Ended	9 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Oct. 31, 2018	May 31, 2018	Jan. 23, 2018	Jul. 14, 2017
Transfer of Financial Assets Accounted for as Sales [Line Items]
Receivable facility term		1 year
Receivable facility renewal term		6 months
Billed and unbilled sold receivables	$ 691,000,000	$ 2,100,000,000
Receivable transfers as sales outstanding	$ 169,000,000	169,000,000
Collection of receivables sold		$ 9,000,000
Line of Credit | MARPA Facility
Transfer of Financial Assets Accounted for as Sales [Line Items]
Maximum borrowing capacity			$ 300,000,000
Perspecta Enterprise Solutions LLC
Transfer of Financial Assets Accounted for as Sales [Line Items]
Total availability under the Receivables Facility				$ 450,000,000	$ 300,000,000	$ 200,000,000