Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Operating Activities
Net income	$ 521,019	$ 683,987
Adjustments to reconcile net income to net cash provided by operating activities:
Loss on the sale of investments, net	2,312	7,648
Loss (income) from other invested assets	10,697	(36,275)
Distribution of income from other invested assets	3,797	11,149
Depreciation and amortization	3,183	2,230
Stock-based compensation expense	13,939	13,707
Amortization of premium on investment securities	10,442	14,654
Deferred income tax provision	(19,583)	49,106
Change in:
Accrued investment income	(3,489)	(3,052)
Accounts receivable	(6,664)	(11,811)
Deferred policy acquisition costs	535	1,770
Prepaid federal income tax	(42,926)	(45,100)
Other assets	66,599	(50,722)
Reserve for losses and LAE	10,256	(194,951)
Unearned premium reserve	(15,197)	(15,972)
Other accrued liabilities	(7,372)	(9,912)
Net cash provided by operating activities	547,548	416,456
Investing Activities
Net change in short-term investments	(482,796)	(18,052)
Purchase of investments available for sale	(858,678)	(1,022,095)
Proceeds from maturity of investments available for sale	591,403	183,232
Proceeds from sales of investments available for sale	468,537	673,945
Purchase of other invested assets	(28,987)	(69,019)
Return of investment from other invested assets	2,783	1,490
Net cash paid for acquisitions	(86,761)	0
Purchase of property and equipment	(1,843)	(2,511)
Net cash used in investing activities	(396,342)	(253,010)
Financing Activities
Treasury stock acquired	(55,870)	(97,770)
Payment of issuance costs for credit facility	0	(154)
Dividends paid	(79,797)	(67,546)
Net cash used in financing activities	(135,667)	(165,470)
Net increase (decrease) in cash	15,539	(2,024)
Cash at beginning of year	81,240	81,491
Cash at end of period	96,779	79,467
Supplemental Disclosure of Cash Flow Information
Income tax payments	(53,337)	(73,226)
Interest payments	(21,229)	(8,044)
Noncash Transactions
Lease liabilities arising from obtaining right-of-use assets	$ 25,117	$ 10,096