Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Fixed-maturities available for sale, amortized cost	$ 5,648,303	$ 5,599,111
Trading securities, amortized cost	99,005	110,484
Equity securities, cost	149,266	92,124
Reinvested cash collateral held under securities lending agreements	98,397	149,364
Reinsurance recoverables, paid losses	$ 174	$ 59
Common stock, par value (in usd per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	485,000	485,000
Common stock, shares, issued (in shares)	171,898	173,247
Common stock, shares, outstanding (in shares)	151,148	153,179
Treasury stock (in shares)	20,750	20,068