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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Business Segment Information (Schedule of Balance Sheet Information by Reportable Segment) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Total assets	$ 5,364	$ 5,052
Goodwill	1,265	1,265		$ 968
Equity in and advances to related companies	850	724	$ 452
Government Solutions
Segment Reporting Information [Line Items]
Goodwill	978	977		$ 679
Operating Segments \| Government Solutions
Segment Reporting Information [Line Items]
Total assets	2,749	2,804
Goodwill	978	977
Equity in and advances to related companies	151	114
Operating Segments \| Technology Solutions
Segment Reporting Information [Line Items]
Total assets	222	204
Goodwill	50	51
Equity in and advances to related companies	0	0
Operating Segments \| Energy Solutions
Segment Reporting Information [Line Items]
Total assets	1,497	1,271
Goodwill	237	237
Equity in and advances to related companies	699	610
Other
Segment Reporting Information [Line Items]
Total assets	889	746
Goodwill	0	0
Equity in and advances to related companies	0	0
Subtotal
Segment Reporting Information [Line Items]
Total assets	5,357	5,025
Goodwill	1,265	1,265
Equity in and advances to related companies	850	724
Non-strategic Business
Segment Reporting Information [Line Items]
Total assets	7	27
Goodwill	0	0
Equity in and advances to related companies	$ 0	$ 0