Insurance and Contractholder Liabilities - Unpaid Claims and Claim Expenses - Cigna Healthcare - Activity (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024	Dec. 31, 2023
Held-for-Sale | Medicare Advantage and related Cigna Healthcare businesses
Paid costs related to:
Unpaid claims classified as liabilities of business held for sale				$ 823
Cigna Healthcare
Liability for Claims and Claims Adjustment Expense [Line Items]
Total of incurred but not reported liabilities plus expected claim development on reported claims and reported claims in process	$ 4,500	$ 4,800
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Beginning balance, including held for sale liabilities	5,018	5,092
Less: Reinsurance, including held for sale liabilities	159	236
Beginning balance, net, including held for sale liabilities	4,859	4,856
Incurred costs related to:
Current year	18,163	18,821
Prior years	(297)	(284)
Total incurred	17,866	18,537
Paid costs related to:
Current year	13,019	14,397
Prior years	3,889	3,960
Total paid	16,908	18,357
Less: Divestiture and other	1,323	0
Ending balance, net	4,494
Add: Reinsurance and other amounts recoverable	142
Ending balance	$ 4,636
Ending balance, net, including held for sale liabilities		5,036
Add: Reinsurance, including held for sale liabilities		166
Ending balance, including held for sale liabilities		5,202
Cigna Healthcare | Held-for-Sale | Medicare Advantage and related Cigna Healthcare businesses
Paid costs related to:
Unpaid claims classified as liabilities of business held for sale		$ 900	$ 983