Document and Entity Information Document - shares	9 Months Ended
	Sep. 30, 2017	Oct. 20, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	NORTHROP GRUMMAN CORP /DE/
Entity Central Index Key	0001133421
Document Type	10-Q
Amendment Flag	false
Document Fiscal Year Focus	2017
Document Period End Date	Sep. 30, 2017
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		174,078,522