Fair Value (Narrative) (Details) (USD $)	3 Months Ended				12 Months Ended											3 Months Ended		12 Months Ended		9 Months Ended	12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2011 Highest Quality Most Over Collateralized Insurance Only Tranches Discount Rate [Member]	Dec. 31, 2011 Lowest Credit Quality Tranches Discount Rate [Member]	Dec. 31, 2011 AAA [Member]	Dec. 31, 2011 BBB [Member]	Dec. 31, 2011 A-Rated Bonds [Member]	Dec. 31, 2011 OREO Properties [Member]	Dec. 31, 2010 OREO Properties [Member]	Dec. 31, 2011 Maximum [Member]	Sep. 30, 2011 Minimum [Member]	Dec. 31, 2011 Minimum [Member]	Dec. 31, 2011 Minimum [Member] Highest Quality Most Over Collateralized Insurance Only Tranches Discount Rate [Member]	Dec. 31, 2011 Worst [Member]	Sep. 30, 2011 Best [Member]	Dec. 31, 2011 Best [Member]	Dec. 31, 2011 First Priority Original AAA Rated Bonds Discount Rate [Member] Maximum [Member]	Dec. 31, 2011 First Priority Original AAA Rated Bonds Discount Rate [Member] Minimum [Member]	Dec. 31, 2011 First Priority Original AAA Rated Bonds Discount Rate [Member] Average [Member]	Dec. 31, 2011 Lower Priority Original AAA Rated Bonds Discount Rate [Member] Maximum [Member]	Dec. 31, 2011 Lower Priority Original AAA Rated Bonds Discount Rate [Member] Minimum [Member]	Dec. 31, 2011 Lower Priority Original AAA Rated Bonds Discount Rate [Member] Average [Member]	Dec. 31, 2011 Original A Rated Bonds Discount Rate [Member] Maximum [Member]	Dec. 31, 2011 Original A Rated Bonds Discount Rate [Member] Minimum [Member]	Dec. 31, 2011 Original A Rated Bonds Discount Rate [Member] Average [Member]	Dec. 31, 2011 Original BBB Rated Bonds Discount Rate [Member] Maximum [Member]	Dec. 31, 2011 Original BBB Rated Bonds Discount Rate [Member] Minimum [Member]	Dec. 31, 2011 Original BBB Rated Bonds Discount Rate [Member] Average [Member]	Dec. 31, 2011 Level 1 [Member]	Dec. 31, 2010 Level 1 [Member]	Dec. 31, 2011 Level 2 [Member]	Dec. 31, 2010 Level 2 [Member]	Dec. 31, 2011 Level 3 [Member]	Dec. 31, 2010 Level 3 [Member]	Dec. 31, 2011 Level 3 [Member] Municipal Securities [Member]	Dec. 31, 2011 Third Party Pricing Service [Member] Level 2 [Member]	Dec. 31, 2011 Third Party Pricing Service [Member] Level 3 [Member]	Dec. 31, 2011 Licensed Internal Third Party [Member] Level 3 [Member]	Dec. 31, 2011 Market Corroborative Data [Member] Level 2 [Member]	Dec. 31, 2011 Market Corroborative Data [Member] Level 2 [Member] FAMC Securities [Member]
Derivatives, Fair Value [Line Items]
Fair value of AFS securities	$ 3,230,795,000				$ 3,230,795,000	$ 4,205,742,000																												$ 159,932,000	$ 934,434,000	$ 1,991,915,000	$ 1,808,921,000	$ 1,078,948,000	$ 1,462,387,000	$ 17,000,000	$ 1,800,000,000	$ 152,000,000	$ 910,000,000	$ 6,000,000	$ 157,000,000
Percentage of bank issuers are public companies					30.00%
Probability of default, Number of base points for year 1 through 5		30
Probability of default, number of base points for each year from year 1 to 5		30
Probability of default, increase to number of base points for each year from year 1 to 5	48
Percentage of probability of default for years 6																65.00%
Deferring collateral rate by a calibration adjustment		65.00%
Percentage of resulting five-year PDs																			100.00%	1.49%	2.18%
Weighted average assumed loss rate on deferring collateral		27.00%	35.00%	35.00%	26.00%	30.00%	44.00%
Percentage of surviving banks with performance improvement pattern				7.00%
Valuations for bank and insurance tranches utilized a discount rate range of LIBOR								3.75%	39.80%									6.23%
Discount rate range of LIBOR															66.20%		11.00%
Discount rate range of LIBOR utilized for fair value purposes																						7.60%	6.20%		8.80%	6.30%		31.70%	6.70%		39.80%	14.50%
Discount rate average of LIBOR utilized for fair value purposes																								6.50%			6.80%			17.60%			33.30%
Percentage of difference between rated bonds										6.00%	31.00%	16.00%
Current interest deferral period without causing default, years					5
Net gain on sale of OREO properties					(58,676,000)	(136,232,000)	(92,920,000)						20,200,000	15,500,000
Carrying value of OREO properties	153,178,000				153,178,000	299,577,000							275,900,000	344,900,000
Impairment of OREO properties													$ 34,800,000	$ 51,900,000