Basis of Presentation (Schedule of Cash Activity) (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash and cash equivalents	$ 522	$ 555	$ 548
Program cash	73	85	80
Restricted cash	4		1
Total cash and cash equivalents, program and restricted cash	$ 599	$ 644	$ 629	$ 642