Acquisitions (Schedule of recognized identifiable assets acquired and liabilities assumed) (Details) - USD ($) $ in Millions		Sep. 30, 2023		Jul. 01, 2023	Dec. 31, 2022		Sep. 30, 2022	Jul. 01, 2022	Dec. 31, 2021	Jan. 01, 2021
Business Acquisition [Line Items]
Accrued investment income		$ 1,040			$ 941
Insurance and reinsurance balances receivable		13,907			11,933
Reinsurance recoverable on losses and loss expenses		19,750	[1]		18,859	[2]
Reinsurance recoverable on policy benefits	[1],[2]	315			302
Value of business acquired		3,675			3,702
Other assets		7,591			7,546
Total assets		222,748			199,017
Unpaid losses and loss expenses		79,705			75,747		$ 75,336		$ 72,330
Unearned premiums		22,684			19,713
Future policy benefits		13,109			10,476		9,906			$ 7,652
Policyholders' account balances		7,178			3,140		3,008		$ 2,766
Insurance and reinsurance balances payable		8,481			7,780
Accounts payable, accrued expenses, and other liabilities		8,422			7,148
Deferred tax liabilities		759			377
Repurchase agreements (refer to Note 3 for balances associated with VIEs)		2,617			1,419
Total liabilities		165,244			148,498
Net acquired assets, including goodwill		52,373			50,519		47,675
Equity, Attributable to Noncontrolling Interest		5,131			0
Total shareholders' equity		57,504			50,519		$ 47,675
Total liabilities and shareholders’ equity		$ 222,748			$ 199,017
Cigna's Life Insurance Business in Asia-Pacific Markets [Member]
Business Acquisition [Line Items]
Investments and Cash								$ 5,274
Accrued investment income								33
Insurance and reinsurance balances receivable								52
Reinsurance recoverable on losses and loss expenses								3
Reinsurance recoverable on policy benefits								85
Value of business acquired								3,633
Goodwill and intangible assets								1,486
Other assets								648
Total assets								11,214
Unpaid losses and loss expenses								12
Unearned premiums								60
Future policy benefits								3,856
Insurance and reinsurance balances payable								115
Accounts payable, accrued expenses, and other liabilities								926
Deferred tax liabilities								886
Repurchase agreements (refer to Note 3 for balances associated with VIEs)								2,000
Total liabilities								5,855
Net acquired assets, including goodwill								5,359
Total liabilities and shareholders’ equity								$ 11,214
Huatai Group
Business Acquisition [Line Items]
Investments and Cash				$ 13,346
Accrued investment income				60
Insurance and reinsurance balances receivable				277
Reinsurance recoverable on losses and loss expenses				581
Reinsurance recoverable on policy benefits				27
Value of business acquired				309
Goodwill and intangible assets				5,049
Other assets				748
Total assets				20,397
Unpaid losses and loss expenses				831
Unearned premiums				800
Future policy benefits				2,287
Policyholders' account balances				4,014
Insurance and reinsurance balances payable				644
Accounts payable, accrued expenses, and other liabilities				702
Deferred tax liabilities				232
Repurchase agreements (refer to Note 3 for balances associated with VIEs)				1,269
Total liabilities				10,779
Net acquired assets, including goodwill				4,408
Equity, Attributable to Noncontrolling Interest				5,210
Total shareholders' equity				$ 9,618

[1] Net of valuation allowance for uncollectible reinsurance.

[2] Net of valuation allowance for uncollectible reinsurance.