Cover Page - shares	3 Months Ended
	Mar. 28, 2021	Apr. 16, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 28, 2021
Document Transition Report	false
Entity File Number	1-11437
Entity Registrant Name	LOCKHEED MARTIN CORPORATION
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	52-1893632
Entity Address, Address Line One	6801 Rockledge Drive,
Entity Address, City or Town	Bethesda,
Entity Address, State or Province	MD
Entity Address, Postal Zip Code	20817
City Area Code	301
Local Phone Number	897-6000
Title of 12(b) Security	Common Stock, $1 par value
Trading Symbol	LMT
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		277,933,985
Entity Central Index Key	0000936468
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Amendment Flag	false