Amounts in Paragraphs - Fair Value of Financial Instruments (Unaudited) (Details 2) - USD ($) $ in Millions	Sep. 30, 2021	Sep. 02, 2021	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Foreign Currency Derivative Instruments Not Designated as Hedging Instruments, Asset at Fair Value	$ 132		$ 133
Foreign Currency Cash Flow Hedge Derivative at Fair Value, Net	$ 0		$ 0
Principal Amount - NGSC Notes		$ 422
Principal Amount - Northrop Grumman Corporation Notes		$ 422