Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Available-for-sale securities at fair value:
Equity securities (cost: 2012 - $1,436,540; 2011 - $775,741)	$ 1,424,014		$ 870,950
Debt securities (amortized cost: 2012 - $15,593,278; 2011 - $2,538,872)	15,999,538		2,679,528
Short-term investments	366,044		1,096,517
Marketable Securities, Total	17,789,596		4,646,995
Other invested assets	537,350		179,815
Total investments	18,326,946		4,826,810
Cash	649,524		84,749
Accrued investment income	165,857		28,879
Premium balances receivable	585,195		147,006
Reinsurance recoverables	1,348,599	[1]	852,845
Ceded unearned premiums	154,980		142,946
Deferred acquisition costs	303,515		70,537
Property and equipment at cost, net of accumulated depreciation and amortization	34,118		17,906
Goodwill	83,447		48,095
Intangible assets, net of amortization	128,773		90,863
Current taxes receivable	79,933
Net deferred tax assets	532,569		80,975
Other assets	414,511		86,478
Total assets	22,807,967		6,478,089
Liabilities and Stockholders' Equity
Loss and loss adjustment expenses	12,239,766		2,313,035
Unearned premiums	1,705,342		549,740
Senior Notes	1,811,483		299,035
Reinsurance payable	67,654		45,462
Current taxes payable			16,247
Other liabilities	579,935		328,893
Total liabilities	16,404,180		3,552,412
Common stock (shares authorized: 2012 and 2011 - 22,000,000; issued 2012 -17,478,746; 2011 - 9,117,787)	17,479		9,118
Contributed capital	3,619,912		938,037
Accumulated other comprehensive income	250,508		155,532
Treasury stock, at cost (2012 - 588,123 shares; 2011 - 566,141 shares)	(175,818)		(167,319)
Retained earnings	2,691,706		1,990,309
Total stockholders' equity	6,403,787		2,925,677
Total liabilities and stockholders' equity	$ 22,807,967		$ 6,478,089

[1] Reinsurance recoverables reflect amounts due from one or more reinsurance subsidiaries of the listed company.