Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 191,164	$ 152,198	$ 403,072
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	40,657	40,735	35,692
Net realized investment gains	(58,397)	(57,089)	(346,444)
Bond amortization, net	4,615	1,062	6,655
Excess tax benefit from exercise of stock options	(56)	(132)	(5)
(Increase) decrease in premiums receivable	(7,819)	(4,192)	17,138
Decrease in current and deferred income taxes	45,431	11,399	150,850
(Increase) decrease in deferred policy acquisition costs	(851)	5,287	24,139
Decrease in unpaid losses and loss adjustment expenses	(48,926)	(19,129)	(80,174)
Increase (decrease) in unearned premiums	10,048	(11,161)	(35,111)
(Decrease) increase in accounts payable and accrued expenses	(9,985)	(9,054)	15,757
Decrease in trading securities in nature, net of realized gains and losses	0	0	3,209
Share-based compensation	899	812	763
Decrease in other payables	(4,142)	(23,186)	(2,742)
Other, net	(4,113)	4,231	(3,774)
Net cash provided by operating activities	158,525	91,781	189,025
CASH FLOWS FROM INVESTING ACTIVITIES
Fixed maturities available for sale in nature: Purchases	(379,963)	(432,869)	(430,692)
Sales	217,535	204,543	238,308
Calls or maturities	418,616	285,454	218,037
Equity securities available for sale in nature:
Purchases	(351,198)	(272,519)	(295,513)
Sales	325,562	240,764	337,018
Calls	0	4,826	0
Net (decrease) increase in payable for securities	(9,137)	10,763	1,192
Net (increase) decrease in short-term investments	(93,737)	12,815	48,718
Purchase of fixed assets	(18,079)	(28,886)	(36,336)
Sale of fixed assets	2,990	1,341	369
Business acquisition, net of cash acquired	0	0	(115,488)
Other, net	12,026	6,868	2,690
Net cash provided by (used in) investing activities	124,615	33,100	(31,697)
CASH FLOWS FROM FINANCING ACTIVITIES
Dividends paid to shareholders	(132,142)	(129,863)	(127,617)
Excess tax benefit from exercise of stock options	56	132	5
Payment to retire senior notes	(125,000)	0	0
Payoff bank loan	(18,000)	0	0
Proceeds from stock options exercised	1,951	733	393
Proceeds from bank loan	20,000	0	120,000
Net cash used in financing activities	(253,135)	(128,998)	(7,219)
Net increase (decrease) in cash	30,005	(4,117)	150,109
Cash:
Beginning of year	181,388	185,505	35,396
End of year	211,393	181,388	185,505
SUPPLEMENTAL CASH FLOW DISCLOSURE
Interest paid	6,193	6,607	7,244
Income taxes paid	$ 8,503	$ 18,792	$ 17,615