BORROWINGS, SUBORDINATED DEBENTURES AND BROKERED DEPOSITS (Details) (USD $)	3 Months Ended		3 Months Ended	1 Months Ended										3 Months Ended		3 Months Ended				3 Months Ended				3 Months Ended				3 Months Ended				3 Months Ended				3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Maximum	Mar. 31, 2012 FHLB advances	Mar. 31, 2013 FHLB advances	Dec. 31, 2012 FHLB advances	Mar. 31, 2013 FHLB 3.16% December 11, 2017	Mar. 31, 2012 FHLB 3.16% December 11, 2017	Mar. 31, 2013 FHLB 2.61% January 11, 2018	Mar. 31, 2012 FHLB 2.61% January 11, 2018	Mar. 31, 2013 FHLB secured lines of credit	Mar. 31, 2013 Federal Reserve discount window	Mar. 31, 2013 Unsecured lines of credit	Mar. 31, 2013 Non-recourse notes	Dec. 31, 2012 Non-recourse notes	Mar. 31, 2013 Subordinated debentures item	Mar. 31, 2012 Trust I and Trust CI	Mar. 31, 2013 Trust CI	Mar. 31, 2012 Trust CI	Mar. 31, 2013 Trust V	Apr. 26, 2013 Trust V	Jan. 28, 2013 Trust V	Dec. 31, 2012 Trust V	Mar. 31, 2013 Trust VI	Apr. 26, 2013 Trust VI	Jan. 28, 2013 Trust VI	Dec. 31, 2012 Trust VI	Mar. 31, 2013 Trust CII	Apr. 26, 2013 Trust CII	Jan. 28, 2013 Trust CII	Dec. 31, 2012 Trust CII	Mar. 31, 2013 Trust VII	Apr. 26, 2013 Trust VII	Jan. 28, 2013 Trust VII	Dec. 31, 2012 Trust VII	Mar. 31, 2013 Trust CIII	Apr. 26, 2013 Trust CIII	Jan. 28, 2013 Trust CIII	Dec. 31, 2012 Trust CIII	Mar. 31, 2013 Trust I	Mar. 31, 2012 Trust I	Mar. 31, 2013 Bank Federal Reserve discount window
Borrowings, subordinated debentures and brokered deposits
Non-recourse debt														$ 11,196,000	$ 12,591,000
Weighted average interest rate on non-recourse debt (as a percent)														6.29%	6.28%
Weighted average remaining maturity of non-recourse debt														2 years 3 months 18 days
Outstanding FHLB advances					0	0
Remaining borrowing capacity											993,900,000
Carrying value of securities pledged	157,500,000				16,500,000
Borrowing capacity												381,900,000	80,000,000																													486,500,000
Total subordinated debentures	108,250,000	108,250,000																		10,310,000			10,310,000	10,310,000			10,310,000	5,155,000			5,155,000	61,856,000			61,856,000	20,619,000			20,619,000
Current Rate (as a percent)																					3.38%	3.41%			3.33%	3.36%			3.23%	3.26%			3.03%	3.05%			1.97%	2.00%
Rate Index																				3 month LIBOR				3 month LIBOR				3 month LIBOR				3 month LIBOR				3 month LIBOR
Spread on variable rate (as a percent)																				3.10%				3.05%				2.95%				2.75%				1.69%
Number of series of subordinated debentures issued																5
Maturity period of debt from the date of issue																30 years
Amount of trust preferred securities issued	105,000,000
Trust preferred securities included in Tier I capital, as a percentage of sum of core capital elements			25.00%
Trust preferred securities included in Tier I capital	105,000,000
Number of months for which cumulative and among other requirements net earnings are not sufficient for dividend payments due for those periods, requiring prior notification to FRB																12 months
Fixed interest rates (as a percent)							3.16%		2.61%									11.00%																						10.60%
Debt termination expense related to prepayment of debt				22,600,000
Redemption of debt				225,000,000				200,000,000		25,000,000							18,600,000		10,300,000																						8,300,000
Brokered Deposits
Amount of customer deposits that were participated with other FDIC-insured financial institutions through the CDARS program as a means to provide FDIC deposit insurance coverage for the full amount of the entity's customer deposits	$ 48,300,000	$ 37,700,000