Revenue from Contracts with Customers - Disaggregation of Revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disaggregation of Revenue [Line Items]
Revenue	$ 2,826	$ 2,693	$ 2,879
Intersegment Sales
Disaggregation of Revenue [Line Items]
Revenue	(26)	(23)	(20)
ASC | Prime contractor
Disaggregation of Revenue [Line Items]
Revenue	858	918	1,209
ASC | Subcontractor
Disaggregation of Revenue [Line Items]
Revenue	948	794	712
ASC | Firm-Fixed Price
Disaggregation of Revenue [Line Items]
Revenue	1,522	1,494	1,667
ASC | Flexibly Priced
Disaggregation of Revenue [Line Items]
Revenue	284	218	254
ASC | Intersegment Sales
Disaggregation of Revenue [Line Items]
Revenue	(25)	(21)	(19)
ASC | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	1,831	1,733	1,940
IMS | Prime contractor
Disaggregation of Revenue [Line Items]
Revenue	252	186	174
IMS | Subcontractor
Disaggregation of Revenue [Line Items]
Revenue	768	795	784
IMS | Firm-Fixed Price
Disaggregation of Revenue [Line Items]
Revenue	851	853	831
IMS | Flexibly Priced
Disaggregation of Revenue [Line Items]
Revenue	169	128	127
IMS | Intersegment Sales
Disaggregation of Revenue [Line Items]
Revenue	(1)	(2)	(1)
IMS | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	1,021	983	959
United States | ASC
Disaggregation of Revenue [Line Items]
Revenue	1,537	1,543	1,808
United States | IMS
Disaggregation of Revenue [Line Items]
Revenue	1,006	956	913
International | ASC
Disaggregation of Revenue [Line Items]
Revenue	269	169	113
International | IMS
Disaggregation of Revenue [Line Items]
Revenue	$ 14	$ 25	$ 45