Unaudited Consolidated Statements of Income (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Revenues
Net premiums written	$ 810,535	$ 820,233	$ 1,763,311	$ 1,683,844
Change in unearned premiums	(51,719)	(93,577)	(251,725)	(276,876)
Net premiums earned	758,816	726,656	1,511,586	1,406,968
Net investment income	68,369	73,608	134,041	147,905
Net realized gains	12,652	34,867	70,992	78,988
Other-than-temporary impairment losses	(724)	(2,454)	(2,972)	(3,485)
Less investment impairments recognized in other comprehensive income, before taxes	0	503	2	511
Net impairment losses recognized in earnings	(724)	(1,951)	(2,970)	(2,974)
Fee income	902	806	1,440	1,349
Equity in net income of investment funds accounted for using the equity method	10,941	7,787	24,764	32,613
Other income (loss)	834	695	2,078	(7,373)
Total revenues	851,790	842,468	1,741,931	1,657,476
Expenses
Losses and loss adjustment expenses	418,653	399,693	818,056	794,900
Acquisition expenses	131,677	128,289	259,269	247,251
Other operating expenses	127,408	117,701	247,591	224,173
Interest expense	5,852	7,439	11,750	14,960
Net foreign exchange gains	(13,811)	(31,689)	(38,075)	(11,001)
Total expenses	669,779	621,433	1,298,591	1,270,283
Income before income taxes	182,011	221,035	443,340	387,193
Income tax expense	5,071	767	9,924	2,669
Net income	176,940	220,268	433,416	384,524
Preferred dividends	5,485	7,649	10,969	14,110
Loss on repurchase of preferred shares	0	10,612	0	10,612
Net income available to common shareholders	$ 171,455	$ 202,007	$ 422,447	$ 359,802
Net income per common share
Basic (per share)	$ 1.31	$ 1.50	$ 3.22	$ 2.68
Diluted (per share)	$ 1.26	$ 1.46	$ 3.11	$ 2.61
Weighted average common shares and common share equivalents outstanding
Basic (shares)	131,377,274	134,529,129	131,143,885	134,241,876
Diluted (shares)	135,849,050	138,211,736	135,624,226	138,017,490