Operating Information by Segment and Geographic Area - Total Assets (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Segment Reporting Information [Line Items]
Total assets	$ 7,100	$ 6,973
Reportable Segments | Energy Solutions
Segment Reporting Information [Line Items]
Total assets	847	1,053
Reportable Segments | Urban Solutions
Segment Reporting Information [Line Items]
Total assets	1,462	1,211
Reportable Segments | Mission Solutions
Segment Reporting Information [Line Items]
Total assets	676	577
Reportable Segments | Other
Segment Reporting Information [Line Items]
Total assets	218	509
Corporate
Segment Reporting Information [Line Items]
Total assets	$ 3,897	$ 3,623