Comprehensive Loss - Schedule of Changes in Accumulated Other Comprehensive Income (Loss) ("AOCL") by Component (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accumulated Other Comprehensive Income Loss [Line Items]
AOCL, Beginning Balance	$ (21)	$ (14)
Other comprehensive (loss) income before reclassifications	7	(6)
Amounts reclassified from AOCL		(1)
Other comprehensive income (loss)	7	(7)	$ (2)
AOCL, Ending Balance	(14)	(21)	(14)
Change in Fair Value of Available for Sale Debt Securities
Accumulated Other Comprehensive Income Loss [Line Items]
AOCL, Beginning Balance	(19)	(2)
Other comprehensive (loss) income before reclassifications	6	(16)
Amounts reclassified from AOCL		(1)
Other comprehensive income (loss)	6	(17)
AOCL, Ending Balance	(13)	(19)	(2)
Change in Unrecognized Pension Cost Components
Accumulated Other Comprehensive Income Loss [Line Items]
AOCL, Beginning Balance	(2)	(12)
Other comprehensive (loss) income before reclassifications	1	10
Other comprehensive income (loss)	1	10
AOCL, Ending Balance	$ (1)	$ (2)	$ (12)