Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash flows from operating activities [Abstract]
Net income (loss)	$ 302,150	$ (1,805,867)	$ (147,879)
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Net (gains) losses on investments and other financial instruments, change in fair value of derivatives and net impairment losses recognized in earnings	(1,022,699)	630,539	(259,261)
Net payments related to derivative contracts and VIE debt	(119,888)	(291,936)	(38,044)
Equity in net income of affiliates	(65)	(14,668)	(33,226)
Distributions from affiliates	0	29,498	11,040
Gain on sale of affiliate	0	(34,815)	0
Proceeds from sales of trading securities (See Note 2)	0	0	4,286,336
Purchases of trading securities (See Note 2)	0	0	(3,880,824)
Net cash received (paid) for commutations, terminations and recaptures	(92,599)	85,657	(369,926)
Deferred income tax provision (benefit)	6,758	381,408	(55,344)
Depreciation and other amortization, net	63,120	39,789	20,080
Change in:
Unearned premiums	(46,665)	(136,291)	(178,677)
Deferred policy acquisition costs	8,420	11,949	19,954
Reinsurance recoverables	86,047	58,266	(197,764)
Reserve for losses and LAE	(194,486)	252,908	629,873
Reserve for premium deficiency	(7,092)	(14,621)	(61,504)
Prepaid federal income taxes	0	0	248,828
Other Assets	65,388	(34,405)	3,641
Accounts payable and accrued expenses	53,836	(20,014)	30,342
Net cash (used in) provided by operating activities	(897,775)	(862,603)	27,645
Cash flows from investing activities:
Proceeds from sales of fixed-maturity investments available for sale	136,217	1,218,460	2,463,626
Proceeds from sales of equity securities available for sale	52,014	15,033	33,807
Proceeds from sales of trading securities (See Note 2)	6,028,267	4,735,215	536,601
Proceeds from redemptions of fixed-maturity investments available for sale	32,214	50,846	199,551
Proceeds from redemptions of fixed-maturity investments held to maturity	8,775	9,035	18,171
Purchases of fixed-maturity investments available for sale	0	0	(308,831)
Purchases of trading securities	(5,456,565)	(6,126,303)	(2,577,599)
Purchases of equity securities available for sale	0	0	(2,908)
Sales and redemptions of short-term investments, net	276,082	(86,071)	(271,041)
Purchases of other invested assets, net	(1,373)	(33,501)	(3,616)
Proceeds from the sale of investment in affiliate	0	172,017	0
Purchases of property and equipment, net	(2,976)	(2,516)	(4,300)
Net cash provided by (used in) investing activities	1,072,655	(47,785)	83,461
Cash flows from financing activities:
Dividends paid	(1,330)	(1,202)	(827)
Issuance of long-term debt	0	391,310	0
Paydown of other borrrowings	0	0	(100,000)
Redemption of long-term debt	(160,000)	(29,348)	(45,622)
Issuance of common stock	0	525,887	0
Excess tax benefits from stock based awards	4	0	0
Net cash (used in) provided by financing activities	(161,326)	886,647	(146,449)
Effect of exchange rate changes on cash	1,701	2,501	1,088
Increase (decrease) in cash	15,255	(21,240)	(34,255)
Cash, beginning of period	20,334	41,574	75,829
Cash, end of period	35,589	20,334	41,574
Supplemental disclosures of cash flow information:
Income taxes (received) paid	1,573	(386)	(335,497)
Interest paid	$ 48,643	$ 40,786	$ 49,224