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, 2023		Dec. 31, 2022
Goodwill [Roll Forward]
Balance at beginning of period	$ 16,228		$ 15,213
Foreign exchange revaluation and other	66		(176)
Goodwill, Purchase Accounting Adjustments	(2)
Balance at end of period	19,686	[1]	16,228
goodwill attributable to noncontrolling interests	759
North America Commercial P&C Insurance
Goodwill [Roll Forward]
Balance at beginning of period	6,945		6,972
Foreign exchange revaluation and other	1		(27)
Goodwill, Purchase Accounting Adjustments	0
Balance at end of period	6,946	[1]	6,945
North America Personal P&C Insurance [Member]
Goodwill [Roll Forward]
Balance at beginning of period	2,230		2,240
Foreign exchange revaluation and other	1		(10)
Goodwill, Purchase Accounting Adjustments	0
Balance at end of period	2,231	[1]	2,230
North America Agricultural Insurance [Member]
Goodwill [Roll Forward]
Balance at beginning of period	134		134
Foreign exchange revaluation and other	0		0
Goodwill, Purchase Accounting Adjustments	0
Balance at end of period	134	[1]	134
Overseas General Insurance [Member]
Goodwill [Roll Forward]
Balance at beginning of period	4,605		4,653
Foreign exchange revaluation and other	87		(138)
Goodwill, Purchase Accounting Adjustments	8
Balance at end of period	5,262	[1]	4,605
Global Reinsurance [Member]
Goodwill [Roll Forward]
Balance at beginning of period	371		371
Foreign exchange revaluation and other	0		0
Goodwill, Purchase Accounting Adjustments	0
Balance at end of period	371	[1]	371
Life Insurance [Member]
Goodwill [Roll Forward]
Balance at beginning of period	1,943		843
Foreign exchange revaluation and other	(23)		(1)
Goodwill, Purchase Accounting Adjustments	(10)
Balance at end of period	4,742	[1]	1,943
Cigna's Life Insurance Business in Asian Markets
Goodwill [Roll Forward]
Goodwill, Acquired During Period			1,191
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			$ 1,101
Huatai Group [Member]
Goodwill [Roll Forward]
Goodwill, Acquired During Period	3,394
Huatai Group [Member] | North America Commercial P&C Insurance
Goodwill [Roll Forward]
Goodwill, Acquired During Period	0
Huatai Group [Member] | North America Personal P&C Insurance [Member]
Goodwill [Roll Forward]
Goodwill, Acquired During Period	0
Huatai Group [Member] | North America Agricultural Insurance [Member]
Goodwill [Roll Forward]
Goodwill, Acquired During Period	0
Huatai Group [Member] | Overseas General Insurance [Member]
Goodwill [Roll Forward]
Goodwill, Acquired During Period	562
Huatai Group [Member] | Global Reinsurance [Member]
Goodwill [Roll Forward]
Goodwill, Acquired During Period	0
Huatai Group [Member] | Life Insurance [Member]
Goodwill [Roll Forward]
Goodwill, Acquired During Period	$ 2,832

[1] At December 31, 2023, Goodwill from Huatai Group includes approximately $759 million attributable to noncontrolling interests