Affordable Care Act - Net Receivables (Payables) for Each of the Ongoing Programs (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Affordable Care Act [Abstract]
Risk adjustment receivable	$ 1,088	$ 838
Risk adjustment payable	(2,303)	(780)
Minimum medical loss ratio	(233)	(103)
Cost sharing reduction receivable	2	0
Cost sharing reduction payable	$ (87)	$ (99)