AFFORDABLE HOUSING PARTNERSHIPS AND OTHER INVESTMENTS (Details) (USD $)	12 Months Ended
	Dec. 31, 2012 item	Dec. 31, 2011 item	Dec. 31, 2010 item
AFFORDABLE HOUSING PARTNERSHIPS AND OTHER INVESTMENTS
Minimum compliance period to fully utilize the tax credits	15 years
Investments in affordable housing partnerships	$ 185,600,000	$ 144,400,000
Tax credit partnerships, Amount
Equity method	142,507,000	94,874,000
Cost method	42,591,000	48,587,000
Total tax credit partnerships	185,098,000	143,461,000
Tax exempt bonds	547,000	984,000
Grand total	185,645,000	144,445,000
Tax credit partnerships, Count
Equity method (number of investments)	35	26
Cost method (number of investments)	16	17
Grand Total (number of investments)	51	43
Other investments in affordable housing partnerships	45,900,000	49,700,000
Total unfunded commitments for investments	84,600,000	86,000,000
Usage of federal tax credits	18,700,000	11,100,000	12,400,000
Remaining tax credits	161,400,000
Investment amortization	18,100,000	17,300,000	10,000,000
Impairment charge		1,300,000
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 and other investments		$ 3,700,000	$ 1,200,000