Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Statement of Cash Flows [Abstract]
Cash provided from (used for) operating activities	$ 724,923	$ 804,141
Investments sold or matured:
Fixed maturities available for sale—sold	510,904	145,824
Fixed maturities available for sale—matured or other redemptions	85,385	138,259
Mortgage loans	26,071	9,913
Other long-term investments	14,125	49,680
Total investments sold or matured	636,485	343,676
Acquisition of investments:
Fixed maturities—available for sale	(923,096)	(623,023)
Mortgage loans	(92,167)	(66,437)
Other long-term investments	(165,322)	(24,749)
Total investments acquired	(1,180,585)	(714,209)
Net (increase) decrease in policy loans	(19,057)	(18,692)
Net (increase) decrease in short-term investments	(18,820)	42,993
Additions to property and equipment	(26,738)	(25,629)
Investments in low-income housing interests	(17,870)	(38,276)
Cash provided from (used for) investing activities	(626,585)	(410,137)
Cash provided from (used for) financing activities:
Issuance of common stock	29,763	42,181
Cash dividends paid to shareholders	(43,681)	(41,569)
Repayment of debt	0	(165,612)
Proceeds from issuance of debt	0	170,000
Payment for debt issuance costs	0	(693)
Net borrowing from FHLB	180,000	0
Net borrowing (repayment) of commercial paper	(114,494)	(25,371)
Proceeds from commercial paper with original maturities greater than 90 days	339,518	0
Repayment of commercial paper with original maturities greater than 90 days	(236,786)	0
Acquisition of treasury stock	(359,342)	(269,031)
Net receipts (payments) from deposit-type products	85,236	(116,437)
Cash provided from (used for) financing activities	(119,786)	(406,532)
Effect of foreign exchange rate changes on cash	6,206	(5,020)
Net increase (decrease) in cash	(15,242)	(17,548)
Cash at beginning of year	103,156	92,559
Cash at end of period	$ 87,914	$ 75,011