Description of the Plan (Details)	12 Months Ended
Dec. 31, 2025 USD ($)
EBP 018
EBP, Description of Plan [Line Items]
Transfers into the plan	$ 35,900,000
EBP 019
EBP, Description of Plan [Line Items]
Transfers into the plan	3,500,000
EBP 020
EBP, Description of Plan [Line Items]
Transfers into the plan	4,100,000
EBP 021
EBP, Description of Plan [Line Items]
Transfers into the plan	2,700,000
EBP 055
EBP, Description of Plan [Line Items]
Transfers into the plan	$ 46,176,000
Maximum annual compensation to total compensation, percentage	40.00%
Automatic deferral rate	3.00%
Automatic deferral rate, annual increase	1.00%
Initial transfer	$ 500
Subsequent transfers	500
Minimum borrowing, amount	$ 500
Maximum borrowing, to total account, percentage	50.00%
Maximum borrowing, amount	$ 50,000
Time period for loans used to reduce maximum borrowing amount	12 months
Basis spread on variable rate	1.00%
EBP 055 \| Minimum
EBP, Description of Plan [Line Items]
Matching percentage	0.00%
EBP 055 \| Maximum
EBP, Description of Plan [Line Items]
Automatic deferral rate	8.00%
Matching percentage	8.00%

EBP, Note Receivable From Participant, Account, Time Period For Loans Used To Reduce Maximum Borrowing Amount

No definition available.

Name:	lmt_EBPNoteReceivableFromParticipantAccountTimePeriodForLoansUsedToReduceMaximumBorrowingAmount
Namespace Prefix:	lmt_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Annual increase in percentage of eligible compensation contributed for participant automatically enrolled in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) until the contribution reaches maximum threshold.

+ References

No definition available.

+ Details

Name:	lmt_EBPParticipantContributionAutomaticAnnualIncreaseDeferralRate
Namespace Prefix:	lmt_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

EBP, Participant Contribution, Maximum Contribution to Eligible Compensation, Percentage

+ References

No definition available.

+ Details

Name:	lmt_EBPParticipantContributionMaximumContributionToEligibleCompensationPercentage
Namespace Prefix:	lmt_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

EBP, Participant Loan, Basis Spread On Variable Rate

+ References

No definition available.

+ Details

Name:	lmt_EBPParticipantLoanBasisSpreadOnVariableRate
Namespace Prefix:	lmt_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

EBP, Self-Directed Brokerage Account, Initial Transfer

+ References

No definition available.

+ Details

Name:	lmt_EBPSelfDirectedBrokerageAccountInitialTransfer
Namespace Prefix:	lmt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

EBP, Self-Directed Brokerage Account, Subsequent Transfers

+ References

No definition available.

+ Details

Name:	lmt_EBPSelfDirectedBrokerageAccountSubsequentTransfers
Namespace Prefix:	lmt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of net asset available for benefit transferred to (from) employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) from (to) external plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 962
-SubTopic 325
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478873/962-325-55-17

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6A-05(a)(Schedule III))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478416/962-205-50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section 45
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477063/962-205-45-8

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitTransferToFromExternalPlan
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- 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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478416/962-205-50-1

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of employer matching contribution on eligible participant contribution to employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanEmployerContributionMatchingPercentage
Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of maximum account balance that participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) can borrow.

+ References

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMaximumBorrowingAmount
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Percentage of maximum account balance that participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) can borrow to total participant account balance.

+ References

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMaximumBorrowingToTotalAccountPercentage
Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of minimum account balance that participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) can borrow.

+ References

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMinimumBorrowingAmount
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Percentage of eligible compensation contributed for participant automatically enrolled in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanParticipantContributionAutomaticDeferralRate
Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	dei_LegalEntityAxis=lmt_EBP018Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=lmt_EBP019Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=lmt_EBP020Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=lmt_EBP021Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=lmt_EBP055Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: