Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Statement of Cash Flows [Abstract]
Cash provided from (used for) operating activities	$ 693,390	$ 702,039
Investments sold or matured:
Fixed maturities available for sale—sold	219,027	74,710
Fixed maturities available for sale—matured or other redemptions	305,656	108,815
Other long-term investments	48,334	4,490
Total investments sold or matured	573,017	188,015
Acquisition of investments:
Fixed maturities—available for sale	(717,994)	(415,134)
Other long-term investments	(157,913)	(141,975)
Total investments acquired	(875,907)	(557,109)
Net (increase) decrease in policy loans	(7,553)	1,291
Net (increase) decrease in short-term investments	(46,679)	(264,140)
Additions to properties	(13,627)	(23,727)
Investments in low-income housing interests	(37,181)	(19,732)
Cash provided from (used for) investing activities	(407,930)	(675,402)
Cash provided from (used for) financing activities:
Issuance of common stock	34,734	66,328
Cash dividends paid to shareholders	(40,208)	(39,891)
Proceeds from issuance of debt	250,492	325,000
Payment for debt issuance costs	(5,272)	(7,639)
Net borrowing (repayment) of commercial paper	(150,047)	5,028
Acquisition of treasury stock	(263,421)	(295,584)
Net receipts (payments) from deposit-type products	(33,782)	(30,736)
Cash provided from (used for) financing activities	(207,504)	22,506
Effect of foreign exchange rate changes on cash	2,138	(5,918)
Net increase (decrease) in cash	80,094	43,225
Cash at beginning of year	92,163	94,847
Cash at end of period	$ 172,257	$ 138,072