Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (35)	$ 8	$ (57)	$ 24
Other comprehensive loss:
Unrealized losses on investments	(16)	(12)	(4)	(20)
Total other comprehensive loss	(16)	(12)	(4)	(20)
Comprehensive income (loss)	$ (51)	$ (4)	$ (61)	$ 4