Reclassifications from Accumulated Other Comprehensive Income (Loss) (Components of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 4,324	$ 2,547	$ 497
Other comprehensive income before reclassifications	7
Amounts reclassified from other comprehensive income	(16)
Net current-period other comprehensive loss	(9)	31	13
Ending balance	5,888	4,324	2,547
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	6	(25)	(38)
Net current-period other comprehensive loss	(9)	31	13
Ending balance	(3)	6	$ (25)
Pension and Other Postretirement
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	20
Other comprehensive income before reclassifications	7
Amounts reclassified from other comprehensive income	(16)
Net current-period other comprehensive loss	(9)
Ending balance	11	20
Foreign Currency
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(14)
Other comprehensive income before reclassifications	0
Amounts reclassified from other comprehensive income	0
Net current-period other comprehensive loss	0
Ending balance	$ (14)	$ (14)