Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Premiums written—insurance:
Direct	$ 755,758	$ 788,321	$ 790,052
Assumed	(11,162)	(6,585)	(207,074)
Ceded	(37,349)	(89,855)	(139,130)
Net premiums written	707,247	691,881	443,848
Decrease in unearned premiums	48,778	133,852	382,053
Net premiums earned—insurance	756,025	825,733	825,901
Net investment income	163,520	178,760	214,190
Net gains on investments	202,177	139,944	257,141
Total other-than-temporary impairment ('OTTI') losses	(1,202)	(90)	(9,269)
Losses recognized in other comprehensive income (loss)	0	0	0
Net impairment losses recognized in earnings	(1,202)	(90)	(9,269)
Change in fair value of derivative instruments	628,395	(558,712)	99,958
Net gains (losses) on other financial instruments	193,329	(211,681)	(88,569)
Gain on sale of affiliate	0	34,815	0
Other income	5,599	8,696	14,026
Total revenues	1,947,843	417,465	1,313,378
Expenses:
Provision for losses	1,296,521	1,739,244	1,337,574
Change in reserve for premium deficiency	(7,092)	(14,621)	(61,504)
Policy acquisition costs	52,763	53,469	63,034
Other operating expenses	175,810	191,942	203,770
Interest expense	61,394	41,777	46,010
Total expenses	1,579,396	2,011,811	1,588,884
Equity in net income of affiliates	65	14,668	33,226
Income (Loss) from Equity Method Investments	65	14,668	33,226
Pretax income (loss)	368,512	(1,579,678)	(242,280)
Income tax provision (benefit)	66,362	226,189	(94,401)
Net income (loss)	$ 302,150	$ (1,805,867)	$ (147,879)
Basic net income (loss) per share	$ 2.28	$ (15.74)	$ (1.80)
Diluted net income (loss) per share	$ 2.26	$ (15.74)	$ (1.80)
Weighted-average number of common shares outstanding—basic	132,372	114,697	81,937
Weighted-average number of common and common equivalent shares outstanding—diluted	133,863	114,697	81,937
Dividends per share	$ 0.01	$ 0.01	$ 0.01