Consolidated Balance Sheet Consolidated Balance Sheet (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Assets [Abstract]
Fixed maturity securities	$ 12,088,055	$ 11,616,844
Equity securities	257,059	283,338
Arbitrage trading account	732,279	522,128
Investment funds	984,836	1,067,495
Loans receivable	655,691	343,583
Real estate	530,239	715,242
Total investments	15,248,159	14,548,630
Cash and cash equivalents	842,671	839,738
Premiums and fees receivable	1,748,916	1,557,480
Due from reinsurers	1,464,003	1,533,103
Accrued investment income	123,168	118,329
Prepaid reinsurance premiums	431,933	367,803
Deferred policy acquisition costs	483,714	452,101
Property, furniture and equipment	335,741	339,448
Federal and foreign income taxes	0	44,857
Goodwill	103,565	110,146
Trading account receivables from brokers and clearing organizations	57,454	304,936
Other assets	327,870	335,225
Total assets	21,167,194	20,551,796
Liabilities:
Reserves for losses and loss expenses	10,256,219	10,080,941
Unearned premiums	3,081,888	2,781,437
Due to reinsurers	272,455	276,755
Trading account securities sold but not yet purchased	111,991	162,278
Federal and foreign income taxes	24,779	0
Other liabilities	728,337	848,749
Junior subordinated debentures	339,930	339,800
Senior notes and other debt	1,697,037	1,692,442
Total liabilities	16,512,636	16,182,402
Equity:
Authorized 5,000,000 shares; issued and outstanding - none	0	0
Authorized 500,000,000 shares, issued and outstanding, net of treasury shares, 127,613,325 and 132,233,167 shares, respectively	47,024	47,024
Additional paid-in capital	974,794	967,440
Retained earnings	5,587,824	5,265,015
Accumulated other comprehensive income	333,899	189,391
Treasury stock, at cost, 107,504,593 and 102,884,751 shares, respectively	2,323,828	2,132,835
Total stockholders’ equity	4,619,713	4,336,035
Noncontrolling interests	34,845	33,359
Total equity	4,654,558	4,369,394
Total liabilities and equity	$ 21,167,194	$ 20,551,796