Income Taxes (Details) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2007	Dec. 31, 2013
Tax provision (benefit) [Abstract]
Tax provision (benefit) before valuation allowance	$ 25,030,000	$ (674,000)	$ 65,322,000	$ (17,792,000)
Change in valuation allowance	(24,781,000)	1,010,000	(63,229,000)	20,257,000
Provision for income taxes	249,000	336,000	2,093,000	2,465,000
Change in deferred tax valuation allowance, included in other comprehensive income	6,600,000	(2,600,000)	(21,300,000)	33,900,000
Valuation allowance	919,700,000		919,700,000			1,004,200,000
Net operating loss carryforwards, regular tax basis	2,500,000,000		2,500,000,000
Net operating loss carryforwards for computing the alternative minimum tax	1,600,000,000		1,600,000,000
Information regarding income tax examinations [Abstract]
Amount of IRS assessment for unpaid taxes and penalties related to REMIC issue	197,500,000		197,500,000
Estimate of federal interest that may be due	164,800,000		164,800,000
Amount of payment made related to the IRS assessment on the REMIC issue					65,200,000
Estimate of additional state income taxes and interest that may be due	47,000,000		47,000,000
Amount of IRS assessment for unpaid taxes and penalties related to disallowance of carryback of 2009 net operating loss	261,400,000		261,400,000
Total amount of unrecognized tax benefits	106,000,000		106,000,000
Total amount of the unrecognized tax benefits that would affect our effective tax rate	93,400,000		93,400,000
Unrecognized tax benefits, accrued interest	$ 26,700,000		$ 26,700,000			$ 26,100,000