Distribution upon Separation

No definition available.

Name:	ldos_DistributionuponSeparation
Namespace Prefix:	ldos_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Period extension for portions of intercompany loans.

+ References

No definition available.

+ Details

Name:	ldos_PeriodExtensionForPortionsOfIntercompanyLoans
Namespace Prefix:	ldos_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ 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 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The amount for notes payable (written promise to pay), due to related parties.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.17)
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(k)(1))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

+ Details

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

- Definition

For an unclassified balance sheet, amounts due from parties associated with the reporting entity as evidenced by a written promise to pay.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(k)(1))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.3)
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Related Parties
-URI http://asc.fasb.org/extlink&oid=16382449

+ Details

Name:	us-gaap_NotesReceivableRelatedParties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_RelatedPartyTransactionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_DebtInstrumentAxis=ldos_NotesWhichMatureOnDecemberTwoThousandTwentyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=ldos_NotesWhichMatureOnDecemberTwoThousandFortyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=ldos_NotesWhichMatureOnJulyTwoThousandThirtyThreeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=ldos_NotesWhichMatureOnJulyTwoThousandThirtyTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_ParentCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_SubsidiariesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CounterpartyNameAxis=ldos_SAICMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Related Party Transactions - Additional Information (Detail) - USD ($)	1 Months Ended	11 Months Ended
	Sep. 30, 2013	Jan. 01, 2016	Jan. 30, 2015
Related Party Transaction [Line Items]
Period extension for portions of intercompany loans (years)		1 year
Notes Which Mature In December 2020
Related Party Transaction [Line Items]
Stated interest rate		4.45%
Notes Which Mature In December 2040
Related Party Transaction [Line Items]
Stated interest rate		5.95%	5.95%
Notes Which Mature In July 2033
Related Party Transaction [Line Items]
Stated interest rate		5.50%	5.50%
Notes Which Mature In July 2032
Related Party Transaction [Line Items]
Stated interest rate		7.13%
Leidos Holding Inc. \| Notes Which Mature In July 2033
Related Party Transaction [Line Items]
Notes payable, related parties		$ 300,000,000
Stated interest rate		5.50%
Leidos Holding Inc. \| Notes Which Mature In July 2032
Related Party Transaction [Line Items]
Notes payable, related parties		$ 250,000,000
Stated interest rate		7.13%
Leidos, Inc.
Related Party Transaction [Line Items]
Note receivable from Leidos Holdings, Inc.		$ 1,600,000,000	$ 1,400,000,000
Leidos, Inc. \| Notes Which Mature In December 2020
Related Party Transaction [Line Items]
Notes payable, related parties		$ 450,000,000
Stated interest rate		4.45%
Leidos, Inc. \| Notes Which Mature In December 2040
Related Party Transaction [Line Items]
Notes payable, related parties		$ 300,000,000
Stated interest rate		5.95%
SAIC \| Leidos, Inc.
Related Party Transaction [Line Items]
Distribution upon separation	$ 736,000,000