Segment Information (Unaudited) Unallocated Corporate Income (Details 5) $ in Millions	6 Months Ended
Jun. 30, 2021 USD ($)
Segment Reporting [Abstract]
Pre-tax gain on sale of business	$ 2,000
Unallowable State Taxes and Transactions Costs from Divestiture	$ 192

Unallowable State Taxes and Transactions Costs from Divestiture

No definition available.

Name:	noc_UnallowableStateTaxesAndTransactionsCostsFromDivestiture
Namespace Prefix:	noc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration