Consolidated Statements of Earnings and Comprehensive Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Revenues
Net premiums earned	$ 1,092,775	$ 190,209	$ 2,622,914	$ 555,067
Net investment income	90,514	22,050	234,568	82,174
Net realized capital gains	12,388	22,706	119,829	63,888
Other than temporary impairment losses		(2,756)	(2,907)	(2,756)
Gain on bargain purchase			494,940
Other income	33,843	321	43,434	1,454
Total revenues	1,229,520	232,530	3,512,778	699,827
Costs and Expenses
Net loss and loss adjustment expenses	672,984	121,777	1,587,815	315,418
Commissions, brokerage and other underwriting expenses	253,756	68,239	592,809	198,899
Other operating expenses	47,432	1,757	97,910	18,998
Corporate administration	9,304	2,649	67,691	14,030
Amortization of intangible assets	73,356	838	213,393	2,516
Interest expense	21,764	4,329	46,584	13,049
Total costs and expenses	1,078,596	199,589	2,606,202	562,910
Earnings before income taxes	150,924	32,941	906,576	136,917
Income taxes	25,480	13,783	111,720	31,337
Net earnings	125,444	19,158	794,856	105,580
Other comprehensive income:
Change in unrealized gains (losses), net of deferred taxes of $92,641 and $(71,817) for the three months ended 2012 and 2011, respectively, and $127,043 and $(31,522) for the nine months ended 2012 and 2011, respectively	172,048	(133,375)	235,937	(58,540)
Less: reclassification for net realized capital gains and other than temporary impairment losses, net of taxes of $(4,336) and $(6,983) for the three months ended 2012 and 2011, respectively, and $(40,923) and $(21,396) for the nine months ended 2012 and 2011, respectively	(8,052)	(12,968)	(75,999)	(39,736)
Change in unrealized currency translation adjustment, net of deferred taxes of $5,931 and $0 for the three months ended 2012 and 2011, respectively, and $(352) and $0 for the nine months ended 2012 and 2011, respectively	11,014		(653)
Retirement plans	(25)	(50)	(799)	(229)
Comprehensive income	$ 300,429	$ (127,235)	$ 953,342	$ 7,075
Basic earnings per share	$ 7.41	$ 2.17	$ 53.19	$ 11.89
Diluted earnings per share	$ 7.41	$ 2.03	$ 53.14	$ 11.76