Liability For Uncertain Tax Positions

No definition available.

Name:	ldos_LiabilityForUncertainTaxPositions
Namespace Prefix:	ldos_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Number of Patents Infringed

+ References

No definition available.

+ Details

Name:	ldos_NumberOfPatentsInfringed
Namespace Prefix:	ldos_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	ldos_OtherCommitmentsAndContingenciesLineItems
Namespace Prefix:	ldos_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage Of Net Proceeds From Legal Settlement Receivable

+ References

No definition available.

+ Details

Name:	ldos_PercentageOfNetProceedsFromLegalSettlementReceivable
Namespace Prefix:	ldos_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Surety Bonds, Amount Outstanding

+ References

No definition available.

+ Details

Name:	ldos_SuretyBondsAmountOutstanding
Namespace Prefix:	ldos_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The noncurrent portion of the amount recognized for uncertain tax positions as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.24)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_LiabilityForUncertainTaxPositionsNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of judgment or settlement awarded to (against) the entity in respect of litigation.

+ References

No definition available.

+ Details

Name:	us-gaap_LitigationSettlementAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of loss contingency liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14326-108349

+ Details

Name:	us-gaap_LossContingencyAccrualAtCarryingValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount charged against operating income increasing loss contingency liability, after adjustments to reduce previously estimated charges.

+ References

+ Details

Name:	us-gaap_LossContingencyAccrualProvision
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Unrecognized Tax Benefit

-URI http://asc.fasb.org/extlink&oid=6527854

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 15A

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=SL6600010-109319

+ Details

Name:	us-gaap_UnrecognizedTaxBenefits
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	dei_LegalEntityAxis=ldos_VirnetXIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_GuaranteeObligationsByNatureAxis=us-gaap_PerformanceGuaranteeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_GuaranteeObligationsByNatureAxis=us-gaap_StandbyLettersOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=ldos_SAICMember
Namespace Prefix:
Data Type:	na
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- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=ldos_GovernmentInvestigationsAndReviewsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=ldos_TaxAuditsAndReviewsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=us-gaap_PredecessorMember
Namespace Prefix:
Data Type:	na
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Other Commitments and Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	1 Months Ended	8 Months Ended	0 Months Ended
	Nov. 30, 2012	Sep. 27, 2013	Dec. 17, 2014	Apr. 03, 2015
Other Commitments And Contingencies [Line Items]
Percentage of proceeds obtained	35.00%
Government Investigations And Reviews
Other Commitments And Contingencies [Line Items]
Liability for estimate of loss		$ 27
Loss contingency accrual				46
Tax Audits And Reviews
Other Commitments And Contingencies [Line Items]
Liabilities for uncertain tax positions				20
Other long-term liabilities				5
Unrecognized tax benefits				15
Standby Letters of Credit
Other Commitments And Contingencies [Line Items]
Amount outstanding				67
Performance Guarantee
Other Commitments And Contingencies [Line Items]
Surety bonds				233
Virnet X Inc
Other Commitments And Contingencies [Line Items]
Number of patents infringed	2
Patents transferred and awarded	368		23
SAIC \| Government Investigations And Reviews
Other Commitments And Contingencies [Line Items]
Liability for estimate of loss		18
Predecessor [Member] \| Government Investigations And Reviews
Other Commitments And Contingencies [Line Items]
Liability for estimate of loss		$ 45