Summary of Quarterly Financial Data (Unaudited) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended																12 Months Ended
	Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2011		Sep. 30, 2011		Jun. 30, 2011		Mar. 31, 2011		Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Condensed Financial Statements, Captions [Line Items]
Interest income	$ 240,000		$ 247,676		$ 253,809		$ 262,654		$ 273,303		$ 281,970		$ 288,052		$ 298,432		$ 1,004,140	$ 1,141,756	$ 1,320,581
Net interest income	207,456		212,345		213,356		220,959		227,156		228,603		230,961		237,434		854,117	924,154	986,333
Provision for loan losses	146,526		63,572		44,222		66,049		54,565		102,325		120,159		141,746		320,369	418,795	1,131,274
Income (loss) from continuing operations before income taxes	(72,299)		30,514		37,347		35,916		26,979		37,118		(43,764)		(79,864)		31,477	(59,532)	(849,170)
Income tax expense (benefit)	(796,339)		(211)		(2,105)		(77)		(378)		6,910		(4,764)		(456)		(798,732)	1,312	(15,151)
Net income (loss)	724,040	[1]	30,725	[1]	39,452	[1]	35,993	[1]	27,357	[1]	30,208	[1]	(39,000)	[1]	(79,408)	[1]	830,209	(60,844)	(790,857)
Net income (loss) attributable to common shareholders	709,304	[1]	16,030	[1]	24,803	[1]	21,369	[1]	12,779	[1]	15,667	[1]	(53,504)	[1]	(93,654)	[1]	771,506	(118,712)	(848,188)
Basic earnings per common share:
Net income (loss) attributable to common shareholders (per share)	$ 0.90		$ 0.02		$ 0.03		$ 0.03		$ 0.02		$ 0.02		$ (0.07)		$ (0.12)		$ 0.98	$ (0.15)	$ (1.30)
Net loss attributable to common shareholders (per share)																	$ 0.98	$ (0.15)	$ (1.24)
Diluted earnings per common share:
Net income (loss) attributable to common shareholders (per share)	$ 0.78		$ 0.02		$ 0.03		$ 0.02										$ 0.85	$ (0.15)	$ (1.30)
Net loss attributable to common shareholders (per share)									$ 0.01		$ 0.02		$ (0.07)		$ (0.12)		$ 0.85	$ (0.15)	$ (1.24)
Valuation allowance for deferred tax assets	$ 796,300																$ 802,771	$ (31,844)	$ (320,377)

[1] The fourth quarter of 2012 results reflect a $796.3 million income tax benefit due primarily to the reversal of substantially all of the deferred tax asset valuation allowance. For additional discussion of the valuation allowance for deferred tax assets, see "Part II - Item 8. Financial Statements and Supplementary Data - Note 24 - Income Taxes" of this Report.