Unaudited Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Revenues
Gross premiums written	$ 1,163,243	$ 1,082,205	$ 2,730,726	$ 2,639,766
Net premiums written	1,136,046	1,056,467	2,609,331	2,526,887
(Increase) decrease in unearned premiums	(45,168)	50,978	(528,623)	(354,853)
Net premiums earned	1,090,878	1,107,445	2,080,708	2,172,034
Net investment income	153,506	158,328	300,402	309,962
Net realized and unrealized investment gains (losses)	38,132	78,199	230,867	(34,000)
Other income	2,654	1,596	5,400	3,408
Total revenues	1,285,170	1,345,568	2,617,377	2,451,404
Expenses
Losses and loss expenses and life policy benefits	706,137	814,523	1,282,623	2,421,740
Acquisition costs	232,723	229,251	444,330	437,100
Other operating expenses	106,184	113,694	204,358	217,991
Interest expense	12,223	12,214	24,443	24,514
Amortization of intangible assets	8,893	9,165	17,786	17,992
Net foreign exchange gains	(7,770)	(8,737)	(5,181)	(9,433)
Total expenses	1,058,390	1,170,110	1,968,359	3,109,904
Income (loss) before taxes and interest in (losses) earnings of equity investments	226,780	175,458	649,018	(658,500)
Income tax expense	50,136	50,085	117,310	23,828
Interest in (losses) earnings of equity investments	(498)	(1,188)	4,579	(443)
Net income (loss)	176,146	124,185	536,287	(682,771)
Preferred dividends	15,405	8,631	30,811	17,263
Net income (loss) available to common shareholders	160,741	115,554	505,476	(700,034)
Comprehensive income (loss)
Net Income Loss	176,146	124,185	536,287	(682,771)
Change in currency translation adjustment	(19,157)	6,303	(1,950)	44,084
Change in other accumulated comprehensive income (loss), net of tax	1,055	(1,920)	(56)	(2,155)
Comprehensive income (loss)	$ 158,044	$ 128,568	$ 534,281	$ (640,842)
Per share data
Basic net income (loss)	$ 2.52	$ 1.71	$ 7.82	$ (10.32)
Diluted net income (loss)	$ 2.50	$ 1.69	$ 7.76	$ (10.32)
Weighted average number of common shares outstanding	63,816,027	67,628,052	64,610,127	67,811,366
Weighted average number of common shares and common share equivalents outstanding	64,423,036	68,442,300	65,132,928	67,811,366
Dividends declared per common share	$ 0.62	$ 0.60	$ 1.24	$ 1.15