Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 134,293	$ 111,695
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	27,903	30,596
Net realized investment (gains) losses	(78,656)	14,465
Bond amortization, net	6,613	4,071
Excess tax benefit from exercise of stock options	(116)	(40)
Increase in premiums receivables	(57,518)	(17,204)
Change in current and deferred income taxes	10,848	22,209
Increase in deferred policy acquisition costs	(14,883)	(4,054)
Decrease in unpaid losses and loss adjustment expenses	(6,859)	(55,480)
Increase in unearned premiums	77,849	32,829
Increase in accounts payable and accrued expenses	6,553	1,967
Share-based compensation	312	606
Increase in other payables	10,503	24,659
Other, net	(3,512)	(219)
Net cash provided by operating activities	113,330	166,100
CASH FLOWS FROM INVESTING ACTIVITIES
Fixed maturities available-for-sale in nature: Purchases	(386,262)	(265,648)
Fixed maturities available-for-sale in nature: Sales	78,341	195,551
Fixed maturities available-for-sale in nature: Calls or maturities	328,592	294,230
Equity securities available-for-sale in nature:
Purchases	(236,785)	(292,972)
Sales	172,144	268,783
Calls	923	0
Net decrease in payable for securities	(1,320)	(5,122)
Net decrease (increase) in short-term investments	14,510	(109,175)
Purchase of fixed assets	(12,205)	(12,613)
Sale of fixed assets	1,864	2,922
Other, net	1,904	9,149
Net cash (used in) provided by investing activities	(38,294)	85,105
CASH FLOWS FROM FINANCING ACTIVITIES
Dividends paid to shareholders	(100,469)	(98,680)
Excess tax benefit from exercise of stock options	116	40
Proceeds from stock options exercised	2,098	810
Payment to retire senior notes	0	(125,000)
Net cash used in financing activities	(98,255)	(222,830)
Net (decrease) increase in cash	(23,219)	28,375
Cash:
Beginning of the year	211,393	181,388
End of period	188,174	209,763
SUPPLEMENTAL CASH FLOW DISCLOSURE
Interest paid	1,319	5,286
Income taxes paid	$ 29,330	$ 503