INVESTMENTS IN AFFORDABLE HOUSING PARTNERSHIPS (Details) (USD $)	12 Months Ended
	Dec. 31, 2011 investment Y	Dec. 31, 2010 investment	Dec. 31, 2009
INVESTMENTS IN AFFORDABLE HOUSING PARTNERSHIPS
Minimum compliance period to fully utilize the tax credits (in years)	15
Tax credit partnerships, Amount
Equity method	$ 94,874,000	$ 111,593,000
Cost method	48,587,000	43,481,000
Total tax credit partnerships	143,461,000	155,074,000
Tax exempt bonds	984,000
Grand total	144,445,000	155,074,000
Tax credit partnerships, Count
Equity method (number of investments)	26	29
Cost method (number of investments)	17	17
Grand Total (number of investments)	43	46
Notes payable	52,434,000	49,690,000
Remaining tax credits	183,186,000	168,521,000
Usage of federal tax credits	11,100,000	12,400,000	7,100,000
Investment amortization	14,600,000	9,400,000	7,000,000
Reduction in the UCB affordable housing investments		3,000,000
Number of investments sold	3	1
Amount of investments sold	25,700,000	3,200,000
Loss on sale of investments in affordable housing partnerships	3,700,000	1,200,000
Impairment charge	$ 1,300,000