Insurance and Contractholder Liabilities - Account Balances (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023	Jun. 30, 2023	Dec. 31, 2022
Current
Market risk benefits, current	$ 25	$ 37
Unearned premiums, current, including held for sale liabilities	737	846
Total, current	6,673	6,633
Current insurance and contractholder liabilities	5,616	5,514
Non-current
Market risk benefits, non-current	840	966
Unearned premiums, non-current, including held for sale liabilities	28	22
Total, non-current	10,949	11,421
Non-current insurance and contractholder liabilities	10,449	10,904
Total
Market risk benefits	865	1,003	$ 1,069
Unearned premiums			1,425
Unearned premiums, including held for sale liabilities	765	868
Total	17,622	18,054
Total insurance and contractholder liabilities	16,065	16,418	19,114
Held-for-Sale | Medicare Advantage and related Cigna Healthcare businesses
Current
Insurance and contractholder liabilities current, classified as held for sale	(1,057)	(1,119)
Non-current
Insurance and contractholder liabilities, non-current, classified as held for sale	(500)	(517)
Total
Insurance and contractholder liabilities classified as held for sale	(1,557)	(1,636)
Unpaid claims classified as liabilities of business held for sale	900	823
Unearned premiums classified as liabilities of business held for sale	129	261
Contractholder deposit funds classified as liabilities held for sale	111	123
Cigna Healthcare
Current
Unpaid claims and claim expenses, current, including held for sale liabilities	5,124	5,017
Future policy benefits, current, including held for sale liabilities	90	97
Contractholder deposit funds, current, including held for sale liabilities	10	12
Non-current
Unpaid claims and claim expenses, non-current, including held for sale liabilities	78	75
Future policy benefits, non-current, including held for sale liabilities	506	518
Contractholder deposit funds, non-current, including liabilities held for sale	125	133
Total
Unpaid claims and claim expenses			5,336	$ 4,176
Unpaid claims and claim expenses, including held for sale liabilities	5,202	5,092
Total liability for future policy benefits			595
Future policy benefits, including held for sale liabilities	596	615
Contractholder deposit funds			158
Contractholder deposit funds, including liabilities held for sale	135	145
Cigna Healthcare | Held-for-Sale | Medicare Advantage and related Cigna Healthcare businesses
Total
Future policy benefits classified as liabilities of business held for sale	417	429
Other Operations
Current
Unpaid claims and claim expenses, current	165	99
Future policy benefits, current	162	163
Contractholder deposit funds, current	360	362
Non-current
Unpaid claims and claim expenses, non-current	151	154
Future policy benefits, non-current	3,200	3,375
Contractholder deposit funds, non-current	6,021	6,178
Total
Unpaid claims and claim expenses	316	253	297
Total liability for future policy benefits	3,362	3,538	3,587
Contractholder deposit funds	$ 6,381	$ 6,540	$ 6,647	$ 6,700