Changes in Balance of Accumulated Other Comprehensive Loss (Parenthetical) (Detail) (USD $) In Billions, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accumulated Other Comprehensive Income (Loss) [Line Items]
Post retirement benefit plan adjustments, tax benefits	$ 5.3	$ 7.4	$ 6.1

Tax Benefits Included In Accumulated Other Comprehensive Income Loss Related To Postretirement Benefit Plans

No definition available.

Name:	lmt_TaxBenefitsIncludedInAccumulatedOtherComprehensiveIncomeLossRelatedToPostretirementBenefitPlans
Namespace Prefix:	lmt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration