Document and Entity Information	3 Months Ended
	Mar. 31, 2019 shares
Document And Entity Information [Abstract]
Entity Registrant Name	LOCKHEED MARTIN CORP
Trading Symbol	LMT
Entity Central Index Key	0000936468
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Document Type	10-Q
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding	282,538,809