Commitments and Contingencies - Contingencies (Details) administrator in Thousands, $ in Millions						1 Months Ended			12 Months Ended
	Aug. 02, 2017 individual	Nov. 16, 2016 lawsuit	Sep. 15, 2016 lawsuit	Dec. 17, 2015 USD ($)	May 12, 2015 employee	Oct. 31, 2015 USD ($)	Dec. 31, 2013 lawsuit	Sep. 30, 2013 individual	Apr. 01, 2016 employee	Apr. 03, 2015 administrator	Feb. 02, 2017 joint_venture	May 12, 2016
Loss Contingencies [Line Items]
Number of partially-owned joint ventures involved in possible sanctions law violations | joint_venture											2
DC Navy Yard Litigation
Loss Contingencies [Line Items]
Number of individuals deceased in shooting | individual								12
Number of lawsuits							15
Strauch and Colby v. Computer Sciences Corporation
Loss Contingencies [Line Items]
Number of system administrators for class action, more than | administrator										4
Number of system administrators filed Consent to Join forms | administrator										1
Strauch and Colby v. Computer Sciences Corporation | Subsequent event
Loss Contingencies [Line Items]
Number of individuals involved in collective action | individual	700
Settled litigation | DC Navy Yard Litigation
Loss Contingencies [Line Items]
Number of lawsuits			9
Settled litigation | Civil Complaint Against Eric Pulier
Loss Contingencies [Line Items]
Former employees under investigation | employee					2
Litigation settlement | $				$ 16.5
Former employees who pled guilty | employee									1
Loss contingency, legal fees percentage												80.00%
Pending litigation | DC Navy Yard Litigation
Loss Contingencies [Line Items]
Number of lawsuits		6
Pending litigation | Kemper Corporate Services, Inc. v. Computer Sciences Corporation
Loss Contingencies [Line Items]
Loss contingency, damages sought | $						$ 100.0