Health Care Costs Payable - Narrative (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred but not reported (IBNR) claims liability, net	$ 7,900
Health Insurance Product Line
Liability for Claims and Claims Adjustment Expense [Line Items]
Decrease in prior years' healthcare costs payable	$ 670	$ 771