Unaudited Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
CASH FLOWS PROVIDED BY OPERATING ACTIVITIES:
Net income	$ 534,154	$ 91,448
Adjustments to reconcile net income to cash provided by operating activities:
Net realized gains on sales of investments	(63,625)	(78,001)
Mark to market adjustments	(225,425)	61,912
Stock compensation expense	13,118	16,917
Changes in:
Reserve for losses and loss expenses, net of reinsurance recoverables	151,041	284,310
Unearned premiums, net of prepaid reinsurance	202,545	165,412
Insurance balances receivable	(102,820)	(77,343)
Reinsurance balances payable	(4,107)	(4,269)
Net deferred acquisition costs	(27,193)	(18,267)
Net deferred tax assets	1,850	(4,081)
Accounts payable and accrued liabilities	(2,996)	7,564
Other items, net	23,677	45,903
Net cash provided by operating activities	500,219	491,505
CASH FLOWS USED IN INVESTING ACTIVITIES:
Purchases of available for sale securities	0	(727)
Purchases of trading securities	(6,328,719)	(5,555,249)
Purchases of other invested assets	(52,578)	(265,720)
Sales of available for sale securities	215,318	627,392
Sales of trading securities	5,778,138	4,841,580
Sales of other invested assets	110,429	40,129
Purchases of fixed assets	(2,041)	(7,792)
Change in restricted cash	35,685	63,120
Net cash used in investing activities	(243,768)	(257,267)
CASH FLOWS USED IN FINANCING ACTIVITIES:
Dividends paid - partial par value reduction	(54,721)	(14,295)
Proceeds from the exercise of stock options	9,104	5,317
Share repurchase	(204,746)	(60,000)
Repurchase of founder warrants	0	(53,620)
Net cash used in financing activities	(250,363)	(122,598)
Effect of exchange rate changes on foreign currency cash	(567)	685
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	5,521	112,325
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	633,996	756,995
CASH AND CASH EQUIVALENTS, END OF PERIOD	639,517	869,320
Supplemental disclosure of cash flow information:
- Cash paid for income taxes	18,912	6,294
- Cash paid for interest expense	$ 45,750	$ 45,750