Insurance and Contractholder Liabilities - Unpaid Claims and Claim Expenses - Cigna Healthcare - Activity (Details) - Cigna Healthcare - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Liability for Claims and Claims Adjustment Expense [Line Items]
Total of incurred but not reported liabilities plus expected claim development on reported claims, including reported claims in process	$ 4,600	$ 4,200
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Beginning balance	4,176	4,261
Less: Reinsurance and other amounts recoverable	221	261
Beginning balance, net	3,955	4,000
Incurred costs related to:
Current year	9,041	8,024
Prior years	(144)	(276)
Total incurred	8,897	7,748
Paid costs related to:
Current year	5,316	4,634
Prior years	2,795	2,822
Total paid	8,111	7,456
Ending balance, net	4,741	4,292
Add: Reinsurance and other amounts recoverable	218	199
Ending balance	$ 4,959	$ 4,491