MORTGAGE SERVICING RIGHTS - Balance of loans serviced for others and fair value of mortgage servicing rights (Details) (Balance of loans serviced for others and fair value of mortgage servicing rights, USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Balance of loans serviced for others and fair value of mortgage servicing rights
Residential mortgage loans serviced for others	$ 137,186	$ 144,197
Fair value of mortgage servicing rights	$ 1,355	$ 1,646