Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Investments:
Fixed income securities, held-to-maturity – at carrying value (fair value: $18,556 – 2024; $21,923 – 2023)	$ 19,496	$ 22,700
Less: allowance for credit losses	0	0
Fixed income securities, held-to-maturity, net of allowance for credit losses	19,496	22,700
Fixed income securities, available-for-sale – at fair value (allowance for credit losses: $31,309 – 2024 and $28,212 – 2023; amortized cost: $8,080,498 – 2024 and $7,880,697 – 2023)	7,669,033	7,499,197
Commercial mortgage loans – at carrying value (fair value: $209,041 – 2024 and $178,913 – 2023)	219,613	188,708
Less: allowance for credit losses	(154)	(291)
Commercial mortgage loans, net of allowance for credit losses	219,459	188,417
Equity securities – at fair value (cost: $187,286 – 2024; $183,076 – 2023)	191,964	187,155
Short-term investments	417,346	309,317
Alternative investments	414,780	395,779
Other investments	89,742	91,164
Total investments (Note 4 and 5)	9,021,820	8,693,729
Cash	160	180
Restricted cash	10,748	13,092
Accrued investment income	72,305	66,339
Premiums receivable	1,600,765	1,331,979
Less: allowance for credit losses (Note 6)	(21,100)	(18,900)
Premiums receivable, net of allowance for credit losses	1,579,665	1,313,079
Reinsurance recoverable	687,288	658,525
Less: allowance for credit losses (Note 7)	(1,700)	(1,700)
Reinsurance recoverable, net of allowance for credit losses	685,588	656,825
Prepaid reinsurance premiums	219,785	203,320
Current federal income tax	38,588	0
Deferred federal income tax	145,897	140,237
Property and equipment – at cost, net of accumulated depreciation and amortization of: $278,525 – 2024; $271,409 – 2023	89,196	83,272
Deferred policy acquisition costs	476,519	424,864
Goodwill	7,849	7,849
Other assets	217,370	199,760
Total assets	12,565,490	11,802,546
Liabilities:
Reserve for loss and loss expense (Note 8)	5,903,525	5,336,911
Unearned premiums	2,598,668	2,330,656
Long-term debt	508,801	503,946
Current federal income tax	0	6,251
Accrued salaries and benefits	92,585	122,003
Other liabilities	539,220	548,398
Total liabilities	9,642,799	8,848,165
Stockholders’ Equity:
Preferred stock of $0 par value per share: Authorized shares 5,000,000; Issued shares: 8,000 with $25,000 liquidation preference per share - 2024 and 2023	200,000	200,000
Common stock of $2 par value per share: Authorized shares 360,000,000 Issued: 105,516,194 – 2024; 105,223,307 – 2023	211,032	210,447
Additional paid-in capital	545,263	522,748
Retained earnings	3,001,054	3,029,396
Accumulated other comprehensive income (loss) (Note 11)	(392,721)	(373,001)
Treasury stock – at cost (shares:  44,656,246 – 2024; 44,586,870 – 2023)	(641,937)	(635,209)
Total stockholders’ equity	2,922,691	2,954,381
Commitments and contingencies
Total liabilities and stockholders’ equity	$ 12,565,490	$ 11,802,546