Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
CASH FROM OPERATING ACTIVITIES:
Net income to common stockholders	$ 503,694	$ 648,884	$ 499,925
Adjustments to reconcile net income to net cash from operating activities:
Net investment gains	(92,324)	(254,852)	(121,544)
Depreciation and amortization	85,139	88,836	103,090
Noncontrolling interests	413	719	5,376
Investment funds	(62,228)	(131,649)	(67,712)
Stock incentive plans	32,123	28,068	23,784
Change in:
Arbitrage trading account	(7,173)	(50,817)	(10,324)
Premiums and fees receivable	(60,942)	(104,174)	(138,027)
Reinsurance accounts	(31,930)	(33,445)	(171,263)
Deferred policy acquisition costs	(29,860)	(42,789)	(52,124)
Increase (Decrease) in Income Taxes	20,428	(40,935)	(45,613)
Current Income Tax Expense (Benefit)	176,832	271,306	139,164
Deferred income taxes	47,260	30,812	56,281
Reserves for losses and loss expenses	397,685	376,617	372,002
Unearned premiums	142,699	277,826	323,160
Other	(63,680)	(58,254)	42,787
Net cash from operating activities	881,304	734,847	819,798
CASH FLOWS USED IN INVESTING ACTIVITIES:
Proceeds from sale of fixed maturity securities	1,388,680	633,459	1,344,707
Proceeds from sale of equity securities	15,833	113,251	267,554
Distributions from (contributions to) investment funds	177,424	69,319	(236,580)
Proceeds from maturities and prepayments of fixed maturity securities	2,999,339	2,605,839	2,718,156
Purchase of fixed maturity securities	(4,455,223)	(4,292,165)	(4,198,135)
Purchase of equity securities	(29,526)	(31,207)	(156,557)
Real estate purchased	(222,659)	(213,159)	(107,352)
Proceeds from Sale of Buildings	0	343,723	0
Change in loans receivable	48,909	21,608	(30,974)
Net additions to property, furniture and equipment	(63,562)	(41,958)	(63,150)
Change in balances due from security brokers	(22,666)	32,617	(26,155)
Proceeds from Divestiture of Businesses, Net of Cash Divested	0	15,783
Payment for business purchased, net of cash acquired	(7,312)	(65,421)	(56,878)
Net cash used in investing activities	(170,763)	(808,311)	(545,364)
CASH FLOWS USED IN FINANCING ACTIVITIES:
Net proceeds from issuance of debt	9,056	354,012	346,822
Net proceeds from stock options exercised	0	0	53
Repayment of senior notes and other debt	(281,086)	(3,700)	(465,389)
Cash dividends to common stockholders	(58,034)	(181,489)	(52,717)
Purchase of common treasury shares	(223,652)	(238,933)	(166,473)
Other	(1,602)	337	7,442
Net cash used in financing activities	(555,318)	(69,773)	(330,262)
Net impact on cash due to change in foreign exchange rates	(66,033)	(22,060)	(10,104)
Net increase (decrease) in cash and cash equivalents	89,190	(165,297)	(65,932)
Cash and cash equivalents at beginning of year	674,441	839,738	905,670
Cash and cash equivalents at end of year	$ 763,631	$ 674,441	$ 839,738