LOANS AND ALLOWANCE FOR LOAN AND LEASE LOSSES - COMPOSITION OF LOANS (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Dec. 31, 2015
Loans disclosures
Total loans	$ 3,957,512		$ 3,810,778
Allowance for loan and lease losses	(40,191)	$ (37,898)	(32,920)	$ (30,436)	$ (29,308)	$ (27,491)
Loans, net	3,917,321		3,777,858
Core Banking Activities
Loans disclosures
Total loans	3,910,381		3,771,831
Allowance for loan and lease losses	(29,546)	(29,251)	(27,928)	(27,091)	(26,857)	(25,792)
Traditional Banking
Loans disclosures
Total loans	3,339,221		3,186,392
Allowance for loan and lease losses	(28,118)	(27,749)	(26,464)	(25,438)	(25,392)	(24,825)
Republic Processing Group
Loans disclosures
Total loans	47,131		38,947
Allowance for loan and lease losses	(10,645)	(8,647)	(4,992)	(3,345)	(2,451)	(1,699)
Residential Real Estate - Owner Occupied | Traditional Banking
Loans disclosures
Total loans	933,726		1,000,148
Allowance for loan and lease losses	(6,573)	(6,740)	(7,158)	(7,417)	(7,893)	(8,301)
Residential Real Estate - Owner Occupied - Correspondent | Traditional Banking
Loans disclosures
Total loans	125,643		149,028
Allowance for loan and lease losses	(314)	(324)	(373)	(392)	(592)	(623)
Residential Real Estate - Non Owner Occupied | Traditional Banking
Loans disclosures
Total loans	193,379		156,605
Allowance for loan and lease losses	(1,337)	(1,237)	(1,139)	(1,165)	(1,052)	(1,052)
Commercial Real Estate | Traditional Banking
Loans disclosures
Total loans	1,161,225		1,060,496
Allowance for loan and lease losses	(8,770)	(8,368)	(8,078)	(8,031)	(7,805)	(7,672)
Construction & land development | Traditional Banking
Loans disclosures
Total loans	138,837		119,650
Allowance for loan and lease losses	(2,076)	(2,508)	(1,850)	(1,408)	(1,332)	(1,303)
Commercial & Industrial | Traditional Banking
Loans disclosures
Total loans	327,214		259,026
Allowance for loan and lease losses	(1,930)	(1,682)	(1,511)	(1,380)	(1,441)	(1,455)
Commercial & Industrial | Republic Processing Group
Loans disclosures
Total loans	265		6,695
Allowance for loan and lease losses			(25)
Lease Financing Receivables | Traditional Banking
Loans disclosures
Total loans	15,367		13,614
Allowance for loan and lease losses	(162)	(151)	(136)	(128)	(115)	(89)
Home equity lines of credit | Traditional Banking
Loans disclosures
Total loans	346,154		341,285
Allowance for loan and lease losses	(3,848)	(3,787)	(3,757)	(3,535)	(3,016)	(2,996)
Consumer: Credit cards | Traditional Banking
Loans disclosures
Total loans	19,898		13,414
Allowance for loan and lease losses	(606)	(588)	(490)	(487)	(456)	(448)
Consumer: Overdrafts | Traditional Banking
Loans disclosures
Total loans	892		803
Allowance for loan and lease losses	(892)	(806)	(675)	(606)	(824)	(351)
Consumer: Automobile loan | Traditional Banking
Loans disclosures
Total loans	63,639		52,579
Allowance for loan and lease losses	(669)	(640)	(526)	(447)	(281)	(56)
Other consumer | Traditional Banking
Loans disclosures
Total loans	13,247		19,744
Allowance for loan and lease losses	(941)	(918)	(771)	(442)	(585)	(479)
Warehouse lines of credit | Warehouse Lending
Loans disclosures
Total loans	571,160		585,439
Allowance for loan and lease losses	(1,428)	(1,502)	(1,464)	(1,653)	(1,465)	(967)
Republic Credit Solutions | Republic Processing Group
Loans disclosures
Total loans	46,866		32,252
Allowance for loan and lease losses	$ (10,645)	$ (8,647)	$ (4,967)	$ (3,345)	$ (2,451)	$ (1,699)