Health Care Costs Payable - Narrative (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred but not reported (IBNR) claims liability, net	$ 8,700
Health Insurance Product Line
Liability for Claims and Claims Adjustment Expense [Line Items]
Decrease in prior years' healthcare costs payable	$ 619	$ 666