BUSINESS COMBINATIONS - fair value of acquired loans (Details) - Floridian Financial Group [Member] $ in Thousands	Mar. 11, 2016 USD ($)
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	$ 288,048
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value	276,275
Commercial Real Estate [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	172,531
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value	167,082
Commercial Loan [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	39,070
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value	37,804
Single Family Residential Real Estate [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	38,304
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value	37,367
Construction Development Land [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	28,572
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value	26,134
Consumer And Other Loans [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	3,385
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value	3,110
Purchased Credit Impaired [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	6,186
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value	$ 4,778