Fair Value - Other Fair Value Disclosures (Details) $ in Millions	3 Months Ended
	Jun. 30, 2017 USD ($) counterparty	Jul. 01, 2016 USD ($)	Mar. 31, 2017 USD ($)	[1]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, net of current maturities	$ 6,249		$ 2,225
Goodwill impairment	0	$ 0
Tangible asset impairment charges	0	0
Impairment of intangible assets	0	0
Impairment of other intangible assets	$ 0	$ 0
Number of counterparties with concentration of credit risk | counterparty	7
Fair value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, net of current maturities	$ 6,200
Carrying value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, net of current maturities	6,100
Foreign Currency Forward Contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Maximum amount of loss the Company could incur	$ 51

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