Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
CASH FLOWS FROM OPERATING ACTIVITIES
Net (loss) income	$ (5,728)	$ 144,877	$ 73,044
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	58,791	55,343	53,258
Net realized investment losses (gains)	133,520	(83,650)	34,255
Increase in premiums receivable	(80,979)	(14,908)	(22,531)
(Increase) decrease in reinsurance recoverables	(164,739)	(43,043)	998
Gain on sale of fixed assets	0	(3,078)	0
Changes in current and deferred income taxes	(13,898)	(3,010)	(2,130)
(Increase) decrease in deferred policy acquisition costs	(16,980)	2,675	936
Increase in loss and loss adjustment expense reserves	318,799	220,365	143,560
Increase in unearned premiums	134,254	27,490	25,124
Increase (decrease) in accounts payable and accrued expenses	6,586	(4,178)	(10,586)
Share-based compensation	145	60	142
Other, net	13,663	42,462	(4,392)
Net cash provided by operating activities	383,434	341,405	291,678
Fixed maturity securities available for sale in nature:
Purchases	(706,224)	(734,397)	(1,077,638)
Sales	189,306	100,709	396,766
Calls or maturities	334,626	575,735	647,059
Equity securities available for sale in nature
Purchases	(1,026,827)	(831,310)	(714,113)
Sales	954,755	679,571	696,138
Calls	0	7,100	0
Changes in securities payable and receivable	4,035	(44,740)	29,958
Decrease (increase) in short-term investments	45,747	73,005	(191,530)
Purchase of fixed assets	(27,959)	(19,443)	(16,979)
Sale of fixed assets	0	6,239	14
Other, net	10,105	1,934	3,605
Net cash used in investing activities	(222,436)	(185,597)	(226,720)
CASH FLOWS FROM FINANCING ACTIVITIES
Dividends paid to shareholders	(138,478)	(137,886)	(137,201)
Employee taxes paid with shares related to share-based compensation	0	0	(3,292)
Proceeds from stock options exercised	358	2,162	1,632
Net proceeds from issuance of senior notes	0	371,011	0
Payoff of principal on loan and credit facilities	0	(320,000)	0
Proceeds from bank loan	0	0	30,000
Net cash used in financing activities	(138,120)	(84,713)	(108,861)
Net increase (decrease) in cash	22,878	71,095	(43,903)
Cash:
Beginning of year	291,413	220,318	264,221
End of year	314,291	291,413	220,318
SUPPLEMENTAL CASH FLOW DISCLOSURE
Interest paid	16,586	9,863	3,531
Income taxes (refunded) paid, net	$ (10,989)	$ 25,218	$ (183)