Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
CASH FROM (USED IN) OPERATING ACTIVITIES:
Net income to common stockholders	$ 349,634	$ 232,572
Adjustments to reconcile net income to net cash from operating activities:
Net investment gains	(161,922)	(53,027)
Depreciation and amortization	50,832	50,617
Noncontrolling interests	227	(847)
Investment funds	(84,385)	(33,057)
Stock incentive plans	13,615	12,395
Change in:
Arbitrage trading account	(12,956)	1,590
Premiums and fees receivable	(197,004)	(162,853)
Reinsurance accounts	(57)	(67,447)
Deferred policy acquisition costs	(31,527)	(34,039)
Income taxes	7,742	(46,642)
Reserves for losses and loss expenses	172,759	221,525
Unearned premiums	297,721	269,931
Other	(150,056)	(76,786)
Net cash from operating activities	254,623	313,932
CASH FROM (USED IN) INVESTING ACTIVITIES:
Proceeds from sale of fixed maturity securities	513,281	555,694
Proceeds from sale of equity securities	112,590	66,969
Distributions from (contributions to) investment funds	211,974	(60,000)
Proceeds from maturities and prepayments of fixed maturity securities	1,214,221	1,561,236
Purchase of fixed maturity securities	(2,034,009)	(2,214,201)
Purchase of equity securities	(48,484)	(111,540)
Real estate sold (purchased)	(63,919)	(13,390)
SEC Schedule III, Real Estate, Cost of Real Estate Sold	343,723	0
Change in loans receivable	(312,071)	(46,854)
Net additions to property, furniture and equipment	(22,555)	(43,446)
Change in balances due to security brokers	28,313	(6,167)
Net cash from businesses sold (purchased)	15,548	(59,964)
Net cash from (used in) investing activities	(41,388)	(371,663)
CASH USED IN FINANCING ACTIVITIES:
Repayment of senior notes and other debt	0	(486,297)
Proceeds from Issuance of Debt	4,988	371,923
Net proceeds from options exercised	53	51
Cash dividends to common stockholders	(26,825)	(12,243)
Purchase of common treasury shares	(197,254)	(31,362)
Other, net	1,365	7,273
Net cash used in financing activities	(217,673)	(150,655)
Net impact on cash due to change in foreign exchange rates	7,371	(38,445)
Net change in cash and cash equivalents	2,933	(246,831)
Cash and cash equivalents at beginning of year	839,738	905,670
Cash and cash equivalents at end of period	$ 842,671	$ 658,839