10-K Consolidated Statements Of Cash Flows - USD ($) $ in Millions	9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating activities
Net income	$ 5,160	$ 5,011	$ 5,888	$ 6,149	$ 4,572
Adjustments to reconcile net income to net cash provided by operating activities:
Net losses on financial instruments	358	439	550	(318)	(182)
Equity in net earnings of other invested assets	70	(304)	(293)	(562)	(51)
Depreciation and amortization	1,321	1,202	1,675	1,302	1,154
Deferred income taxes	(361)	(183)	(115)	342	(540)
Impairment of property and equipment	446	0	7	73	198
Share-based compensation	217	191	264	255	283
Changes in operating assets and liabilities:
Receivables, net	(727)	(678)	(2,510)	(2,138)	(256)
Other invested assets	(46)	46	11	(70)	(32)
Other assets	(936)	(465)	133	41	(283)
Policy liabilities	333	1,588	2,411	2,523	3,528
Unearned income	3,220	2,548	(42)	(113)	202
Accounts payable and other liabilities	1,717	598	824	719	1,978
Income taxes	257	(41)	(338)	140	72
Other, net	3	(35)	(66)	21	45
Net cash provided by operating activities	11,032	9,917	8,399	8,364	10,688
Investing activities
Purchases of investments	(24,337)	(19,612)	(24,946)	(18,669)	(19,492)
Proceeds from sale of investments	7,830	9,402	11,988	10,269	11,318
Maturities, calls and redemptions from investments	14,531	7,606	10,620	4,344	4,741
Changes in securities lending collateral	55	(677)	(301)	(956)	(849)
Purchases of subsidiaries, net of cash acquired	(1,570)	(623)	(649)	(3,476)	(1,976)
Purchases of property and equipment	(970)	(854)	(1,152)	(1,087)	(1,021)
Other, net	(82)	(91)	(120)	(63)	(45)
Net cash used in investing activities	(4,543)	(4,849)	(4,560)	(9,638)	(7,324)
Financing activities
Net proceeds from commercial paper borrowings	0	375	(300)	50	(150)
Proceeds from long-term borrowings	2,574	1,286	3,071	3,462	2,484
Repayments of long-term borrowings	(1,908)	(982)	(1,899)	(1,068)	(1,932)
Proceeds from short-term borrowings	0	1,365	1,365	1,325	970
Repayments of Short-term Debt	(265)	(1,375)	(1,375)	(1,050)	(1,670)
Changes in securities lending payable	(54)	685	302	956	849
Changes in bank overdrafts	(523)	181	933	(376)	486
Repurchase and retirement of common stock	(1,748)	(1,748)	(2,316)	(1,900)	(2,700)
Cash dividends	(1,049)	(924)	(1,229)	(1,104)	(954)
Proceeds from issuance of common stock under employee stock plans	112	152	182	203	176
Taxes paid through withholding of common stock under employee stock plans	(99)	(91)	(93)	(102)	(128)
Other, net	5	16	41	27	2
Net cash (used in) provided by financing activities	(2,955)	(1,060)	(1,318)	423	(2,567)
Effect of foreign exchange rates on cash and cash equivalents	(2)	(16)	(14)	(10)	7
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	3,532	3,992	2,507	(861)	804
Cash and cash equivalents at beginning of period	7,387	4,880	4,880	5,741	4,937
Cash and cash equivalents at end of period	$ 10,919	$ 8,872	$ 7,387	$ 4,880	$ 5,741