Acquisitions - HPES Merger (Details) - USD ($) $ / shares in Units, $ in Millions	Apr. 01, 2017	Jun. 30, 2017	Mar. 31, 2017
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Goodwill		$ 8,774	$ 1,855	[1]
HPES
Business Acquisition [Line Items]
Preliminary fair value of purchase consideration received by HPE stockholders	$ 9,782
Preliminary fair value of HPES options assumed by CSC	68
Total estimated consideration transferred	$ 9,850
Ownership percentage by HPE stockholders	50.10%
Shares transferred to HPE stockholders (in shares)	141,865,656
Net shares transferred to HPE stockholders (in shares)	141,741,712
Cancelled shares (in shares)	123,944
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Cash and cash equivalents	$ 974
Accounts receivable	3,965
Other current assets	769
Total current assets	5,708
Property and equipment	2,482
Intangible assets	5,085
Other assets	1,694
Total assets acquired	14,969
Accounts payable, accrued payroll, accrued expenses, and other current liabilities	(3,843)
Deferred revenue	(879)
Long-term debt, net of current maturities	(3,997)
Long-term deferred tax liabilities and income tax payable	(1,553)
Other liabilities	(1,551)
Total liabilities assumed	(11,823)
Net identifiable assets acquired	3,146
Add: Fair value of non-controlling interests	(61)
Goodwill	6,765
Total estimated consideration transferred	9,850
Preliminary adjustments to receivables	$ 163
Computer Sciences Corporation
Business Acquisition [Line Items]
Closing price (in dollars per share)			$ 69.01

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