Accumulated Other Comprehensive Income (Loss) (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Reclassification adjustments from accumulated other comprehensive income (loss)
Investment revenues, before taxes	$ 6,756	$ 5,747	$ 26,291	$ 21,378
Interest expenses, before taxes	(205,036)	(267,085)	(646,932)	(823,334)
Other revenues - other, before taxes	5,514	1,853	20,874	(19,204)
Income tax effect	55,669	27,146	42,001	74,490
Net loss	(91,395)	(49,973)	(73,686)	(141,178)
Reclassification adjustments
Reclassification adjustments from accumulated other comprehensive income (loss)
Net loss	6	384	1,427	(8,084)
Unrealized gains (losses) on investment securities | Reclassification adjustments
Reclassification adjustments from accumulated other comprehensive income (loss)
Investment revenues, before taxes	10	(601)	2,036	(959)
Income tax effect	(4)	211	(713)	336
Net loss	6	(390)	1,323	(623)
Unrealized gains (losses) on cash flow hedges | Reclassification adjustments
Reclassification adjustments from accumulated other comprehensive income (loss)
Interest expenses, before taxes		899	160	975
Other revenues - other, before taxes		293		(12,453)
Income tax effect		(418)	(56)	4,017
Net loss		$ 774	$ 104	$ (7,461)