LOANS, Acquired Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Credit impaired acquired loans [Abstract]
Outstanding principal balance	$ 6,936	$ 13,242
Carrying amount	5,446	10,115
Credit impaired acquired loans, total balance due	7,000	13,400
Non-impaired acquired loans [Abstract]
Outstanding principal balance	1,271,584	1,658,780
Carrying amount	1,247,691	1,626,979
Total acquired loans [Abstract]
Outstanding principal balance	1,278,520	1,672,022
Carrying amount	1,253,137	1,637,094
Accretable discount related to acquired loans [Roll forward]
Balance at beginning of year	976	498
Merchants acquisition	0	793
Accretion recognized	(783)	(905)
Net reclassification between accretable and non-accretable	244	590
Balance at end of year	$ 437	$ 976