Income Taxes (Tables)

12 Months Ended

Dec. 31, 2011

Income Taxes [Abstract]

Summary Of Income Tax Contingencies

	Fiscal Years
U.S. Internal Revenue Service ("IRS") for the U.S. subsidiaries		2008 — 2011
Inland Revenue for the U.K. branches		2010 — 2011
Irish Revenue Commissioners for the Irish subsidiaries		2007 — 2011
Swiss Federal Tax Administration for the Swiss branch		2008 — 2011
Inland Revenue Department for the Hong Kong branch		2009 — 2011
Inland Revenue Authority for the Singapore branch		2010 — 2011

Schedule Of Income Tax Expense (Benefit) Components

	2011		2010		2009
Current income tax expense	$	30,851	$	14,560	$	38,763
Deferred income tax expense (benefit)		129		12,385		(2,119	)
Income tax expense	$	30,980	$	26,945	$	36,644

Schedule Of Income Sources

	2011		2010		2009
Bermuda	$	133,553	$	609,880	$	537,333
U.S.		63,175		76,084		95,631
Europe		108,800		5,986		10,567
Income before income taxes	$	305,528	$	691,950	$	643,531

Schedule Of Deferred Tax Assets And Liabilities

	2011			2010
Deferred tax assets:
Reserve for losses and loss expenses	$	20,580		$	19,213
Equity compensation		15,920			13,230
Unearned premium		11,382			10,654
Deferred acquisition costs		8,506			6,228
Other-than-temporary impairments		506			514
Mark-to-market on securities acquired		80			1,251
Total deferred tax assets		56,974			51,090
Deferred tax liabilities:
Intangible assets		(16,500	)		(17,448	)
Realized gains		(6,317	)		(1,803	)
Depreciation		(4,391	)		(2,496	)
Unrealized appreciation and timing difference on investments		(3,135	)		(6,168	)
Market discount on bonds		(1,032	)		(1,301	)
Other deferred tax liabilities		(2,953	)		(2,134	)
Total deferred tax liabilities		(34,328	)		(31,350	)
Net deferred tax assets	$	22,646		$	19,740

Schedule Of Effective Income Tax Rates

	2011			2010			2009
Income before taxes	$	305,528		$	691,950		$	643,531
Expected tax rate		7.8	%		7.8	%		0.0	%
Income not subject to income tax		(3.4	)%		(7.8	)%		0.0	%
Foreign taxes at local expected tax rates		6.0	%		3.7	%		5.6	%
Loss on sale of subsidiary		0.0	%		(0.3	)%		0.0	%
Disallowed expenses and capital allowances		0.1	%		0.1	%		0.1	%
Prior year refunds and adjustments		(0.6	)%		0.6	%		(0.1	)%
Other		0.2	%		(0.2	)%		0.1	%
Effective tax rate		10.1	%		3.9	%		5.7	%