Consolidated Statements Of Income And Comprehensive Income (Loss) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
OPERATING REVENUES
Earned premiums	$ 530,537	$ 509,203	$ 1,573,189	$ 1,462,515
Net investment income	64,438	62,199	207,834	196,551
Other-than-temporary impairment losses	(3,159)	(9,846)	(4,151)	(11,553)
Other-than-temporary impairment losses recognized in other comprehensive income (loss)	0	(138)	0	(3,306)
Other-than-temporary impairment losses recognized in net income	(3,159)	(9,984)	(4,151)	(14,859)
Net realized investment gains, excluding other-than-temporary impairment losses	8,390	22,823	29,507	40,282
Net realized investment gains	5,231	12,839	25,356	25,423
Other revenues	165,569	91,847	385,778	260,361
Total Operating Revenues	765,775	676,088	2,192,157	1,944,850
OPERATING EXPENSES
Losses and loss adjustment expenses	303,459	306,632	813,074	927,643
Underwriting, acquisition and insurance expenses	231,841	202,316	695,322	601,511
Amortization of intangible assets	7,959	6,023	25,078	17,586
Other expenses	145,339	70,302	343,462	218,270
Total Operating Expenses	688,598	585,273	1,876,936	1,765,010
Operating Income	77,177	90,815	315,221	179,840
Interest expense	24,692	23,656	69,068	64,516
Income Before Income Taxes	52,485	67,159	246,153	115,324
Income tax expense	811	12,490	45,998	19,145
Net Income	51,674	54,669	200,155	96,179
Net income attributable to noncontrolling interests	2,021	1,405	3,562	4,329
Net Income to Shareholders	49,653	53,264	196,593	91,850
OTHER COMPREHENSIVE INCOME (LOSS)
Net holding gains (losses) arising during the period	100,630	(90,330)	246,056	(5,606)
Unrealized other-than-temporary impairment losses on fixed maturities arising during the period	(128)	189	(136)	1,657
Reclassification adjustments for net gains included in net income	(6,484)	(7,995)	(20,154)	(15,286)
Change in net unrealized gains on investments, net of taxes	94,018	(98,136)	225,766	(19,235)
Change in foreign currency translation adjustments, net of taxes	3,266	(8,133)	2,927	(5,538)
Change in net actuarial pension loss, net of taxes	522	379	1,487	1,080
Total Other Comprehensive Income (Loss)	97,806	(105,890)	230,180	(23,693)
Comprehensive Income (Loss)	149,480	(51,221)	430,335	72,486
Comprehensive income attributable to noncontrolling interests	2,026	1,405	3,520	4,329
Comprehensive Income (Loss) to Shareholders	$ 147,454	$ (52,626)	$ 426,815	$ 68,157
NET INCOME PER SHARE
Basic (in dollars per share)	$ 5.33	$ 5.50	$ 19.72	$ 9.46
Diluted (in dollars per share)	$ 5.32	$ 5.48	$ 19.67	$ 9.42