Amounts in Paragraphs - Debt (Details 3) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Jun. 15, 2022	Sep. 02, 2021	Mar. 01, 2021
Debt Instrument [Line Items]
Credit Facility, Covenant Terms, Maximum Debt to Capitalization Ratio	The company also cannot permit the ratio of its debt to capitalization (as set forth in the credit agreement) to exceed 65 percent.
Line of Credit Facility, Covenant Compliance	the company was in compliance with all covenants under its credit agreement.
Long-term Debt, Fair Value	$ 12,100	$ 15,100
Interest paid, net of interest received	474	570	$ 572
2021 Note, Face Amount						$ 700
2021 Note, Interest Rate, Stated Percentage						3.50%
2022 Note, Face Amount						$ 1,500
2022 Note, Interest Rate, Stated Percentage						2.55%
Redemption Premium		54
Principal Amount - NGSC Notes					$ 422
Principal Amount - Northrop Grumman Corporation Notes					$ 422
Principal Amount - Northrop Grumman Corporation Notes (Unregistered Notes)				$ 414
Principal Amount - Northrop Grumman Corporation Notes (Registered Notes)				$ 414
Five Year Term [Member] [Domain]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	2,500	2,000
Credit facilities	0
Commercial Paper [Member]
Debt Instrument [Line Items]
Commercial Paper, Maximum Borrowing Capacity	2,500	$ 2,000
Short-term Debt	$ 0