Revenue from Contracts with Customers - Disaggregation of Revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Revenue	$ 2,879	$ 2,778	$ 2,714
Intersegment Sales
Disaggregation of Revenue [Line Items]
Revenue	(22)	(22)	(37)
AST | Prime contractor
Disaggregation of Revenue [Line Items]
Revenue	505	443	372
AST | Subcontractor
Disaggregation of Revenue [Line Items]
Revenue	451	485	397
AST | Firm Fixed Price
Disaggregation of Revenue [Line Items]
Revenue	822	813	614
AST | Flexibly Priced
Disaggregation of Revenue [Line Items]
Revenue	134	115	155
AST | Intersegment Sales
Disaggregation of Revenue [Line Items]
Revenue	14	12	12
AST | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	970	940	781
NC&C | Prime contractor
Disaggregation of Revenue [Line Items]
Revenue	704	620	655
NC&C | Subcontractor
Disaggregation of Revenue [Line Items]
Revenue	261	397	374
NC&C | Firm Fixed Price
Disaggregation of Revenue [Line Items]
Revenue	845	903	956
NC&C | Flexibly Priced
Disaggregation of Revenue [Line Items]
Revenue	120	114	73
NC&C | Intersegment Sales
Disaggregation of Revenue [Line Items]
Revenue	7	9	24
NC&C | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	972	1,026	1,053
IMS | Prime contractor
Disaggregation of Revenue [Line Items]
Revenue	174	283	442
IMS | Subcontractor
Disaggregation of Revenue [Line Items]
Revenue	784	550	474
IMS | Firm Fixed Price
Disaggregation of Revenue [Line Items]
Revenue	831	692	763
IMS | Flexibly Priced
Disaggregation of Revenue [Line Items]
Revenue	127	141	153
IMS | Intersegment Sales
Disaggregation of Revenue [Line Items]
Revenue	1	1	1
IMS | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	959	834	917
United States | AST
Disaggregation of Revenue [Line Items]
Revenue	880	821	711
United States | NC&C
Disaggregation of Revenue [Line Items]
Revenue	928	942	988
United States | IMS
Disaggregation of Revenue [Line Items]
Revenue	913	792	895
International | AST
Disaggregation of Revenue [Line Items]
Revenue	76	107	58
International | NC&C
Disaggregation of Revenue [Line Items]
Revenue	37	75	41
International | IMS
Disaggregation of Revenue [Line Items]
Revenue	$ 45	$ 41	$ 21