Consolidated Statements Of Income And Comprehensive Income (Loss) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
OPERATING REVENUES
Earned premiums	$ 965,599	$ 784,819	$ 1,914,974	$ 1,349,406
Net investment income	92,169	77,979	178,884	142,596
Other-than-temporary impairment losses	(1,007)	(4,589)	(1,007)	(4,589)
Net realized investment gains, excluding other-than-temporary impairment losses	8,127	16,135	25,521	34,052
Net realized investment gains	7,120	11,546	24,514	29,463
Other revenues	194,083	157,425	380,254	330,168
Total Operating Revenues	1,258,971	1,031,769	2,498,626	1,851,633
OPERATING EXPENSES
Losses and loss adjustment expenses	610,406	442,406	1,152,709	730,302
Underwriting, acquisition and insurance expenses	365,987	363,095	721,492	591,768
Amortization of intangible assets	13,488	11,292	27,487	20,907
Other expenses	184,942	140,759	367,110	293,076
Total Operating Expenses	1,174,823	957,552	2,268,798	1,636,053
Operating Income	84,148	74,217	229,828	215,580
Interest expense	29,789	28,561	59,488	52,135
Income Before Income Taxes	54,359	45,656	170,340	163,445
Income tax expense	13,218	16,980	41,698	45,506
Net Income	41,141	28,676	128,642	117,939
Net income attributable to noncontrolling interests	1,073	920	858	1,281
Net Income to Shareholders	40,068	27,756	127,784	116,658
OTHER COMPREHENSIVE INCOME (LOSS)
Net holding gains (losses) arising during the period	208,332	(158,690)	355,628	22,909
Change in unrealized other-than-temporary impairment losses on fixed maturities arising during the period	15	(70)	(5)	179
Reclassification adjustments for net gains included in net income	(4,818)	(7,957)	(10,762)	(20,212)
Change in net unrealized gains on investments, net of taxes	203,529	(166,717)	344,861	2,876
Change in foreign currency translation adjustments, net of taxes	6,671	(10,459)	7,584	(11,640)
Change in net actuarial pension loss, net of taxes	325	366	644	736
Total Other Comprehensive Income (Loss)	210,525	(176,810)	353,089	(8,028)
Comprehensive Income (Loss)	251,666	(148,134)	481,731	109,911
Comprehensive income attributable to noncontrolling interests	1,078	920	870	1,281
Comprehensive Income (Loss) to Shareholders	$ 250,588	$ (149,054)	$ 480,861	$ 108,630
NET INCOME PER SHARE
Basic (in dollars per share)	$ 2.67	$ 2.24	$ 8.95	$ 10.83
Diluted (in dollars per share)	$ 2.66	$ 2.24	$ 8.91	$ 10.79