Unaudited Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
CASH FLOWS PROVIDED BY OPERATING ACTIVITIES:
Net income	$ 133,814	$ 328,835
Adjustments to reconcile net income to cash provided by operating activities:
Net realized gains on sales of investments	(58,224)	(99,781)
Mark to market adjustments	35,592	(59,113)
Stock compensation expense	7,871	7,631
Undistributed income of equity method investments	15,987	13,744
Changes in:
Reserve for losses and loss expenses, net of reinsurance recoverables	132,927	101,911
Unearned premiums, net of prepaid reinsurance	160,437	258,006
Insurance balances receivable	(162,313)	(298,440)
Reinsurance recoverable on paid losses	(2,346)	(12,445)
Funds held	261,528	217,985
Reinsurance balances payable	11,479	51,159
Net deferred acquisition costs	(17,622)	(36,598)
Net deferred tax assets	(2,691)	1,934
Accounts payable and accrued liabilities	(54,603)	(53,397)
Other items, net	(34,434)	27,507
Net cash provided by operating activities	427,402	448,938
CASH FLOWS USED IN INVESTING ACTIVITIES:
Purchases of trading securities	(2,854,825)	(3,905,650)
Purchases of other invested assets	(73,131)	(181,419)
Sales of trading securities	2,953,661	3,705,229
Sales of other invested assets	85,502	184,166
Purchases of fixed assets	(17,984)	(5,601)
Change in restricted cash	(26,098)	21,638
Net cash paid for acquisitions	(141,503)	(2,565)
Net cash used in investing activities	(74,378)	(184,202)
CASH FLOWS USED IN FINANCING ACTIVITIES:
Dividends paid	(43,191)	(33,207)
Proceeds from the exercise of stock options	7,389	6,313
Share repurchases	(246,443)	(137,810)
Proceeds from other long-term debt	3,928	0
Net cash used in financing activities	(278,317)	(164,704)
Effect of exchange rate changes on foreign currency cash	(2,199)	3,170
NET INCREASE IN CASH AND CASH EQUIVALENTS	72,508	103,202
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	589,339	531,936
CASH AND CASH EQUIVALENTS, END OF PERIOD	661,847	635,138
Supplemental disclosure of cash flow information:
Cash paid for income taxes	1,922	18,061
Cash paid for interest expense	$ 27,000	$ 27,000