Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Statement of Cash Flows [Abstract]
Cash provided from (used for) operating activities	$ 477,330	$ 397,133
Investments sold or matured:
Fixed maturities available for sale—sold	15,705	75,116
Fixed maturities available for sale—matured or other redemptions	61,560	115,160
Other long-term investments	1,950	20,929
Total investments sold or matured	79,215	211,205
Acquisition of investments:
Fixed maturities—available for sale	(285,505)	(339,145)
Other long-term investments	(47,898)	(122,010)
Total investments acquired	(333,403)	(461,155)
Net (increase) decrease in policy loans	(7,870)	(2,324)
Net (increase) decrease in short-term investments	39,744	11,801
Additions to property and equipment	(8,210)	(6,981)
Investments in low-income housing interests	(17,246)	(27,870)
Cash provided from (used for) investing activities	(247,770)	(275,324)
Cash provided from (used for) financing activities:
Issuance of common stock	37,024	25,931
Cash dividends paid to shareholders	(20,071)	(19,687)
Short-term borrowings from FHLB	45,000	0
Net borrowing (repayment) of commercial paper	20,070	42,348
Acquisition of treasury stock	(179,276)	(119,482)
Net receipts (payments) from deposit-type products	(54,487)	(13,810)
Cash provided from (used for) financing activities	(151,740)	(84,700)
Effect of foreign exchange rate changes on cash	1,729	(1,644)
Net increase (decrease) in cash	79,549	35,465
Cash at beginning of year	92,559	92,163
Cash at end of period	$ 172,108	$ 127,628