10-K Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 10,919			$ 7,387				$ 4,880
Fixed maturities, current	27,811			25,952				26,267
Equity securities	165			953				1,881
Premium receivables	7,883			7,083				5,681
Self-funded receivables	3,756			4,663				4,010
Other receivables	5,293			4,298				3,749
Other current assets	5,358			5,281				4,654
Total current assets	61,185			55,617				51,122
Long-term investments:
Fixed maturities, long-term	816			752				632
Other invested assets	6,118			5,685				5,225
Property and equipment, net	4,248			4,316				3,919
Goodwill	25,291			24,383				24,228	$ 21,691
Other intangible assets	10,491			10,315				10,615
Other noncurrent assets	2,329			1,687				1,715
Total assets	110,478			102,755				97,456
Current Liabilities:
Medical claims payable	16,176			15,596				13,518
Other policyholder liabilities	5,681			5,933				5,521
Unearned income	4,332			1,112				1,153
Accounts payable and accrued expenses	5,983			5,607				4,970
Short-term borrowings	0			265				275
Current portion of long-term debt	799			1,500				1,599
Other current liabilities	10,366			9,683				7,849
Total current liabilities	43,337			39,696				34,885
Long-term debt, less current portion	24,045			22,349				21,157
Reserves for future policy benefits, noncurrent	807			803				753
Deferred tax liabilities, net	1,779			2,015				2,815
Other noncurrent liabilities	1,971			1,562				1,683
Total liabilities	71,939			66,425				61,293
Commitments and contingencies – Note 11
Preferred stock, shares issued	0			0				0
Preferred stock, shares outstanding	0			0				0
Shareholders' equity
Preferred stock, without par value, shares authorized – 100,000,000; shares issued and outstanding – none	$ 0			$ 0				$ 0
Common stock, par value $0.01, shares authorized – 900,000,000; shares issued and outstanding – 234,906,987 and 237,958,067	2			2				2
Additional paid-in capital	8,830			9,084				9,148
Retained earnings	32,103			29,647				27,142
Accumulated other comprehensive loss	(2,512)	$ (2,166)		(2,490)	$ (2,779)	$ (2,151)		(197)	150	$ (296)
Total Shareholders' Balance, beginning	38,423			36,243	$ 36,055			36,095
Noncontrolling interests	116			87				68
Total equity	38,539	$ 38,312	$ 37,460	36,330		$ 35,887	$ 36,059	36,163	$ 33,187	$ 31,693
Total liabilities and equity	$ 110,478			$ 102,755				$ 97,456