CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Cash flows from operating activities:
Net income (loss)	$ (42,978)	$ 583,161
Adjustments to reconcile net income to net cash provided by operating activities:
Net realized investment gains	(125,177)	(117,325)
Net realized and unrealized gains of other investments	(5,890)	(38,476)
Amortization of fixed maturities	65,015	40,004
Other amortization and depreciation	12,245	10,081
Share-based compensation expense	29,583	27,051
Changes in:
Accrued interest receivable	1,044	(3,199)
Reinsurance recoverable balances	(181,469)	(127,440)
Deferred acquisition costs	(118,104)	(100,567)
Prepaid reinsurance premiums	(18,373)	67,035
Reserve for loss and loss expenses	1,302,466	370,395
Unearned premiums	471,944	404,842
Insurance and reinsurance balances, net	307,816	294,096
Other items	(90,857)	45,454
Net cash provided by operating activities	991,633	866,920
Cash flows from investing activities:
Fixed maturities	(12,135,839)	(9,297,089)
Equity securities	(461,103)	(96,209)
Other investments	(180,000)	(45,000)
Short-term investments	(598,997)	(392,794)
Proceeds from the sale of:
Fixed maturities	10,855,038	7,975,262
Equity securities	123,636	48,970
Other investments	61,916	120,680
Short-term investments	491,682	299,913
Proceeds from redemption of fixed maturities	1,114,611	829,109
Proceeds from redemption of short-term investments	125,641	95,647
Purchase of other assets	(18,909)	(11,977)
Change in restricted cash and cash equivalents	(149,981)	(72,089)
Net cash used in investing activities	(772,305)	(545,577)
Cash flows from financing activities:
Net proceeds from issuance of senior notes	0	494,870
Repurchase of shares	(15,781)	(432,415)
Dividends paid - common shares	(176,274)	(83,090)
Dividends paid - preferred shares	(27,656)	(27,656)
Proceeds from issuance of common shares	6,614	4,459
Net cash used in financing activities	(213,097)	(43,832)
Effect of exchange rate changes on foreign currency cash	(530)	(8,261)
Increase in cash and cash equivalents	5,701	269,250
Cash and cash equivalents - beginning of period	929,515	788,614
Cash and cash equivalents - end of period	$ 935,216	$ 1,057,864