COMMITMENTS AND CONTINGENCIES (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
COMMITMENTS AND CONTINGENCIES
Commitments to extend credit	$ 71,222,000	$ 74,283,000
Commitments to extend credit - variable	778,385,000	617,246,000
Total loan commitments	849,607,000	691,529,000
Commitments and contingencies
Commitments to purchase equipment being acquired for lease to others	4,399,000
Commitments to extend credit	881,540,000	723,485,000
Commitments to extend credit related to foreign loans	5,700,000
Commitment to contribute capital to miscellaneous investments	10,800,000	7,100,000
Standby letters of credit
Commitments and contingencies
Credit commitments	$ 27,534,000	$ 31,956,000
Expiration period of guarantees	1 year