Unaudited Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
CASH FLOWS PROVIDED BY OPERATING ACTIVITIES:
Net income	$ 359,750	$ 279,973
Adjustments to reconcile net income to cash provided by operating activities:
Net realized gains on sales of investments	(118,640)	(76,104)
Mark to market adjustments	(5,634)	80,136
Stock compensation expense	10,822	9,282
Undistributed loss (income) of equity method investments	10,452	(4,313)
Changes in:
Reserve for losses and loss expenses, net of reinsurance recoverables	171,229	50,308
Unearned premiums, net of prepaid reinsurance	285,012	248,079
Insurance balances receivable	(260,627)	(229,580)
Funds held	226,727	(38,763)
Reinsurance balances payable	30,405	57,379
Net deferred acquisition costs	(45,166)	(37,941)
Net deferred tax assets	(3,511)	(16,252)
Accounts payable and accrued liabilities	4,473	(18,540)
Other items, net	4,441	34,508
Net cash provided by operating activities	669,733	338,172
CASH FLOWS (USED IN) PROVIDED BY INVESTING ACTIVITIES:
Purchases of trading securities	(5,608,594)	(4,955,817)
Purchases of other invested assets	(242,227)	(211,501)
Sales of trading securities	5,500,176	5,137,280
Sales of other invested assets	243,123	189,155
Purchases of fixed assets	(14,490)	(4,171)
Change in restricted cash	(29,565)	(74,032)
Net cash paid for acquisitions	(2,565)	0
Net cash (used in) provided by investing activities	(154,142)	80,914
CASH FLOWS USED IN FINANCING ACTIVITIES:
Dividends paid - partial par value reduction	0	(12,981)
Dividends paid	(55,064)	(17,117)
Proceeds from the exercise of stock options	7,640	8,465
Share repurchases	(166,207)	(120,163)
Net cash used in financing activities	(213,631)	(141,796)
Effect of exchange rate changes on foreign currency cash	(2,626)	(6,122)
NET INCREASE IN CASH AND CASH EQUIVALENTS	299,334	271,168
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	531,936	681,879
CASH AND CASH EQUIVALENTS, END OF PERIOD	831,270	953,047
Supplemental disclosure of cash flow information:
Cash paid for income taxes	18,052	17,249
Cash paid for interest expense	$ 45,750	$ 45,750