Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash flows from operating activities [Abstract]
Net (loss) income	$ (196,985)	$ (451,468)	$ 302,150
Adjustments to reconcile net (loss) income to net cash used in operating activities:
Net losses (gains) on investments and other financial instruments, change in fair value of derivative instruments and net impairment losses recognized in earnings	186,230	41,409	(1,022,699)
Net payments related to derivative contracts and VIE debt	(37,060)	(8,213)	(119,888)
Equity in net (income) loss of affiliates	(1)	13	(65)
Distributions from affiliates	0	92	0
Gain on sale of affiliate	0	(7,708)	0
Net cash paid for commutations, terminations and recaptures	(307,067)	(240,110)	(92,599)
Commutation - related charges	5,300	36,500	0
Deferred income tax (benefit) provision	(31,820)	6,000	6,758
Depreciation and other amortization, net	80,136	72,389	63,120
Change in:
Unearned premiums	130,289	82,910	(46,665)
Deferred policy acquisition costs	17,976	25,504	8,420
Reinsurance recoverables	42,358	66,385	86,047
Reserve for losses and LAE	(668,248)	(161,114)	(194,486)
Reserve for premium deficiency	(1,901)	41	(7,092)
Other assets	44,804	7,706	65,388
Other liabilities	69,151	19,205	46,744
Net cash provided by (used in) operating activities	(664,937)	(510,500)	(897,775)
Cash flows from investing activities:
Proceeds from sales of fixed-maturity investments available for sale	22,248	79,534	136,217
Proceeds from sales of equity securities available for sale	0	31,235	52,014
Proceeds from sales of trading securities	1,289,726	6,004,371	6,028,267
Proceeds from redemptions of fixed-maturity investments available for sale	9,269	5,909	32,214
Proceeds from redemptions of fixed-maturity investments held to maturity	325	2,076	8,775
Proceeds from redemptions of equity securities available for sale	10,503	0	0
Purchases of fixed-maturity investments available for sale	(110,747)	0	0
Purchases of trading securities	(518,327)	(5,895,099)	(5,456,565)
(Purchases) sales and redemptions of short-term investments, net	(651,506)	484,347	276,082
Sales (purchases) of other assets, net	14,610	(65,090)	(1,373)
Proceeds from the sale of investment in affiliate	0	14,700	0
Purchases of property and equipment, net	(5,802)	(910)	(2,976)
Net cash provided by investing activities	60,299	661,073	1,072,655
Cash flows from financing activities:
Dividends paid	(1,632)	(1,335)	(1,330)
Proceeds/payments related to issuance or exchange of debt, net	377,783	0	0
Redemption of long-term debt	(79,372)	(153,261)	(160,000)
Issuance of common stock	299,410	0	0
Excess tax benefits from stock based awards	752	0	4
Net cash provided by (used in) financing activities	596,941	(154,596)	(161,326)
Effect of exchange rate changes on cash	0	(11)	1,701
(Decrease) increase in cash	(7,697)	(4,034)	15,255
Cash, beginning of period	31,555	35,589	20,334
Cash, end of period	23,858	31,555	35,589
Supplemental disclosures of cash flow information:
Income taxes paid	5,487	2,079	1,573
Interest paid	$ 40,380	$ 38,378	$ 48,643