Unaudited Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Revenues
Gross premiums written	$ 1,567,483	$ 1,557,561
Net premiums written	1,473,286	1,470,419
Increase in unearned premiums	(483,456)	(405,830)
Net premiums earned	989,830	1,064,589
Net investment income	146,896	151,633
Net realized and unrealized investment gains (losses)	192,735	(112,199)
Other income	2,746	1,813
Total revenues	1,332,207	1,105,836
Expenses
Losses and loss expenses and life policy benefits	576,486	1,607,217
Acquisition costs	211,608	207,849
Other operating expenses	98,174	104,297
Interest expense	12,220	12,300
Amortization of intangible assets	8,893	8,827
Net foreign exchange losses (gains)	2,589	(695)
Total expenses	909,970	1,939,795
Income (loss) before taxes and interest in earnings of equity investments	422,237	(833,959)
Income tax expense (benefit)	67,174	(26,258)
Interest in earnings of equity investments	5,078	745
Net income (loss)	360,141	(806,956)
Preferred dividends	15,405	8,631
Net income (loss) available to common shareholders	344,736	(815,587)
Comprehensive income (loss)
Net Income Loss	360,141	(806,956)
Change in currency translation adjustment	17,207	37,781
Change in other accumulated comprehensive loss, net of tax	(1,111)	(235)
Comprehensive income (loss)	$ 376,237	$ (769,410)
Per share data
Basic net income (loss)	$ 5.27	$ (11.99)
Diluted net income (loss)	$ 5.24	$ (11.99)
Weighted average number of common shares outstanding	65,404,227	67,997,426
Weighted average number of common shares and common share equivalents outstanding	65,842,819	67,997,426
Dividends declared per common share	$ 0.62	$ 0.55