Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
CASH FROM (USED IN) OPERATING ACTIVITIES:
Net income to common stockholders	$ 538,173	$ 369,546
Adjustments to reconcile net income to net cash from operating activities:
Net investment gains	(234,180)	(96,896)
Depreciation and amortization	63,415	80,049
Noncontrolling interests	479	367
Investment funds	(150,502)	(48,299)
Stock incentive plans	21,549	18,163
Change in:
Arbitrage trading account	1,781	(249)
Premiums and fees receivable	(125,319)	(161,660)
Reinsurance accounts	12,967	(168,863)
Deferred policy acquisition costs	(44,087)	(51,629)
Income taxes	11,092	(25,396)
Reserves for losses and loss expenses	277,542	341,266
Unearned premiums	345,521	363,354
Other	(143,645)	6,942
Net cash from operating activities	574,786	626,695
CASH USED IN INVESTING ACTIVITIES:
Proceeds from sale of fixed maturity securities	546,970	891,357
Proceeds from sale of equity securities	109,928	222,396
Distributions from (contributions to) investment funds	285,233	(57,812)
Proceeds from maturities and prepayments of fixed maturity securities	1,887,252	2,244,665
Purchase of fixed maturity securities	(3,098,477)	(3,198,204)
Purchase of equity securities	(28,606)	(184,829)
Additions to real estate	(253,007)	(47,279)
SEC Schedule III, Real Estate, Cost of Real Estate Sold	343,723	0
Change in loans receivable	320	(99,356)
Net additions to property, furniture and equipment	(30,797)	(49,425)
Change in balances due to security brokers	68,411	(37,554)
Gain (Loss) on Disposition of Business	15,612	(21,408)
Payment for business purchased, net of cash acquired	(65,423)	(38,556)
Net cash used in investing activities	(218,861)	(376,005)
CASH USED IN (FROM) FINANCING ACTIVITIES:
Repayment of senior notes and other debt	(1,829)	(463,600)
Proceeds from Issuance of Debt	431,409	349,423
Cash dividends to common stockholders	(40,784)	(39,336)
Purchase of common treasury shares	(236,703)	(39,370)
Other, net	915	7,341
Net cash used in (from) financing activities	153,008	(185,542)
Net impact on cash due to change in foreign exchange rates	(6,386)	(4,492)
Net change in cash and cash equivalents	502,547	60,656
Cash and cash equivalents at beginning of year	839,738	905,670
Cash and cash equivalents at end of period	$ 1,342,285	$ 966,326