Schedule II. Condensed Financial Information of Registrant (Parent Company) (Schedule of Condensed Financial Information of Registrant, Statements of Cash Flows) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash Flows from Operating Activities
Net income	$ 894	$ 1,202	$ 690
Adjustments to reconcile net income to net cash flows provided by operating activities:
Net investment losses	199	(120)	54
Other, net	(192)	(76)	(145)
Net cash flows provided by operating activities	2,502	1,997	1,775
Cash Flows from Investing Activities
Change in short term investments	155	(83)	(39)
Other, net	(10)	1	16
Net cash flows used by investing activities	(1,512)	(1,228)	(705)
Cash Flows from Financing Activities
Dividends paid to common stockholders	(982)	(621)	(950)
Proceeds from the issuance of debt	0	0	495
Repayment of debt	0	0	(419)
Purchase of treasury stock	(39)	(18)	(18)
Other, net	(11)	(9)	(10)
Net cash flows used by financing activities	(1,032)	(648)	(902)
Net change in cash	(61)	117	177
Cash, beginning of year	536	419	242
Cash, end of period	475	536	419
Parent Company
Cash Flows from Operating Activities
Net income	894	1,202	690
Adjustments to reconcile net income to net cash flows provided by operating activities:
Equity in net income of subsidiaries	(993)	(1,304)	(812)
Dividends received from subsidiaries	990	880	975
Net investment losses	0	0	20
Other, net	28	33	26
Net cash flows provided by operating activities	919	811	899
Cash Flows from Investing Activities
Change in short term investments	114	(163)	2
Capital contributions to subsidiaries	0	0	(1)
Other, net	0	0	0
Net cash flows used by investing activities	114	(163)	1
Cash Flows from Financing Activities
Dividends paid to common stockholders	(982)	(621)	(950)
Proceeds from the issuance of debt	0	0	495
Repayment of debt	0	0	(419)
Purchase of treasury stock	(39)	(18)	(18)
Other, net	(11)	(8)	(9)
Net cash flows used by financing activities	(1,032)	(647)	(901)
Net change in cash	1	1	(1)
Cash, beginning of year	1	0	1
Cash, end of period	$ 2	$ 1	$ 0