Goodwill, Other intangible assets, and Value of business acquired (Roll-forward of Goodwill by Business Segment) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Goodwill [Roll Forward]
Balance at beginning of period	$ 15,213	$ 15,400
Foreign exchange revaluation and other	(176)	(187)
Balance at end of period	16,287	15,213
North America Commercial P&C Insurance
Goodwill [Roll Forward]
Balance at beginning of period	6,972	6,972
Foreign exchange revaluation and other	(27)	0
Balance at end of period	6,945	6,972
North America Personal P&C Insurance [Member]
Goodwill [Roll Forward]
Balance at beginning of period	2,240	2,240
Foreign exchange revaluation and other	(10)	0
Balance at end of period	2,230	2,240
North America Agricultural Insurance [Member]
Goodwill [Roll Forward]
Balance at beginning of period	134	134
Foreign exchange revaluation and other	0	0
Balance at end of period	134	134
Overseas General Insurance [Member]
Goodwill [Roll Forward]
Balance at beginning of period	4,653	4,836
Foreign exchange revaluation and other	(138)	(183)
Balance at end of period	4,605	4,653
Global Reinsurance [Member]
Goodwill [Roll Forward]
Balance at beginning of period	371	371
Foreign exchange revaluation and other	0	0
Balance at end of period	371	371
Life Insurance [Member]
Goodwill [Roll Forward]
Balance at beginning of period	843	847
Foreign exchange revaluation and other	(1)	(4)
Balance at end of period	2,002	$ 843
Cigna's Life Insurance Business in Asian Markets
Goodwill [Roll Forward]
Goodwill, Acquired During Period	1,250
Cigna's Life Insurance Business in Asian Markets | North America Commercial P&C Insurance
Goodwill [Roll Forward]
Goodwill, Acquired During Period	0
Cigna's Life Insurance Business in Asian Markets | North America Personal P&C Insurance [Member]
Goodwill [Roll Forward]
Goodwill, Acquired During Period	0
Cigna's Life Insurance Business in Asian Markets | North America Agricultural Insurance [Member]
Goodwill [Roll Forward]
Goodwill, Acquired During Period	0
Cigna's Life Insurance Business in Asian Markets | Overseas General Insurance [Member]
Goodwill [Roll Forward]
Goodwill, Acquired During Period	90
Cigna's Life Insurance Business in Asian Markets | Global Reinsurance [Member]
Goodwill [Roll Forward]
Goodwill, Acquired During Period	0
Cigna's Life Insurance Business in Asian Markets | Life Insurance [Member]
Goodwill [Roll Forward]
Goodwill, Acquired During Period	$ 1,160