Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Investments:
Fixed maturity securities	$ 11,826,928	$ 11,312,037
Equity securities available for sale	561,785	443,439
Arbitrage trading account	419,249	397,312
Investment funds	728,505	680,638
Loans receivable	325,073	263,187
Real estate	360,787	342,905
Total investments	14,222,327	13,439,518
Cash and cash equivalents	1,012,220	911,742
Premiums and fees receivable	1,347,305	1,206,204
Due from reinsurers	1,270,036	1,215,679
Accrued investment income	135,702	133,776
Prepaid reinsurance premiums	305,689	258,271
Deferred policy acquisition costs	386,783	364,937
Real estate, furniture and equipment	264,413	262,275
Goodwill	87,865	87,865
Trading account receivables from brokers and clearing organizations	275,844	318,240
Current federal and foreign income taxes	0	9,670
Other assets	153,922	195,696
Total assets	19,462,106	18,403,873
Liabilities:
Reserves for losses and loss expenses	9,488,668	9,337,134
Unearned premiums	2,380,002	2,189,575
Due to reinsurers	299,220	241,204
Trading account securities sold but not yet purchased	40,520	62,514
Current federal and foreign income taxes	15,537	0
Deferred federal and foreign income taxes	31,665	2,835
Other liabilities	881,170	866,229
Junior subordinated debentures	243,102	242,997
Senior notes and other debt	1,865,380	1,500,503
Total liabilities	15,245,264	14,442,991
Equity:
Preferred stock, par value $.10 per share: Authorized 5,000,000 shares; issued and outstanding - none	0	0
Common stock, par value $.20 per share:Authorized 500,000,000 shares, issued and outstanding, net of treasury shares, 138,274,272 and 137,520,019 shares	47,024	47,024
Additional paid-in capital	944,263	941,109
Retained earnings	4,711,836	4,491,162
Accumulated other comprehensive income	416,355	354,851
Treasury stock, at cost, 96,843,646 and 97,597,899 shares	(1,911,694)	(1,880,790)
Total stockholders' equity	4,207,784	3,953,356
Noncontrolling interests	9,058	7,526
Total equity	4,216,842	3,960,882
Total liabilities and equity	$ 19,462,106	$ 18,403,873