10-Q Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended						9 Months Ended		12 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 1,300	$ 1,856	$ 2,004	$ 1,598	$ 1,634	$ 1,779	$ 5,160	$ 5,011	$ 5,888	$ 6,149	$ 4,572
Other comprehensive (loss) income, net of tax:
Change in net unrealized losses/gains on investments	(352)			(639)			(44)	(2,630)	(2,260)	(457)	428
Change in non-credit component of impairment losses on investments	2			(1)			(1)	(3)	(3)	2	0
Change in net unrealized gains/losses on cash flow hedges	1			2			16	8	10	11	12
Change in net periodic pension and postretirement costs	2			7			7	23	(70)	123	(1)
Change in future policy benefits	3			7			2	24	32	(7)	0
Foreign currency translation adjustments	(4)			(7)			(2)	(15)	(13)	(9)	7
Other comprehensive loss	(348)	$ (116)	$ 442	(631)	$ (908)	$ (1,054)	(22)	(2,593)	(2,304)	(337)	446
Net (income) loss attributable to noncontrolling interests	(11)			5			(29)	18	6	9	0
Other comprehensive loss attributable to noncontrolling interests	2			3			0	11	11	2	0
Total shareholders’ comprehensive income	$ 943			$ 975			$ 5,109	$ 2,447	$ 3,601	$ 5,823	$ 5,018