REVENUE FROM CONTRACTS WITH CUSTOMERS (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenue recognition
Net interest income	$ 50,341,000	$ 52,432,000	$ 50,041,000	$ 67,780,000	$ 55,120,000	$ 52,252,000	$ 52,205,000	$ 72,738,000	$ 220,594,000	$ 232,315,000	$ 236,126,000
Noninterest income:
Mortgage banking income									19,994,000	31,847,000	9,499,000
Program fees									14,521,000	7,095,000	4,712,000
Increase in cash surrender value of BOLI									2,242,000	1,585,000	1,550,000
Death benefits in excess of cash surrender value of life insurance	979,000								979,000
Net gain on branch divestiture											7,829,000
Total noninterest income	$ 16,630,000	$ 19,339,000	$ 21,853,000	$ 29,037,000	$ 17,136,000	$ 20,597,000	$ 18,751,000	$ 30,569,000	86,859,000	87,053,000	75,008,000
Total net revenue									$ 307,453,000	$ 319,368,000	$ 311,134,000
Net-revenue concentration (as percent)									100.00%	100.00%	100.00%
Writedowns during entity's holding of property (as a percent)									10.00%
Core Banking Activities
Revenue recognition
Net interest income									$ 183,548,000	$ 186,700,000	$ 184,574,000
Noninterest income:
Mortgage banking income									19,994,000	31,847,000	9,499,000
Increase in cash surrender value of BOLI									2,242,000	1,585,000	1,550,000
Death benefits in excess of cash surrender value of life insurance									979,000
Net gain on branch divestiture											7,829,000
Total noninterest income									51,734,000	59,378,000	48,219,000
Total net revenue									$ 235,282,000	$ 246,078,000	$ 232,793,000
Net-revenue concentration (as percent)									76.00%	77.00%	75.00%
Traditional Banking
Revenue recognition
Net interest income									$ 157,249,000	$ 159,381,000	$ 168,076,000
Noninterest income:
Increase in cash surrender value of BOLI									2,242,000	1,585,000	1,550,000
Death benefits in excess of cash surrender value of life insurance									979,000
Net gain on branch divestiture											7,829,000
Total noninterest income									31,492,000	27,404,000	38,553,000
Total net revenue									$ 188,741,000	$ 186,785,000	$ 206,629,000
Net-revenue concentration (as percent)									61.00%	59.00%	67.00%
Warehouse Lending
Revenue recognition
Net interest income									$ 25,218,000	$ 25,957,000	$ 15,801,000
Noninterest income:
Total noninterest income									57,000	24,000	(46,000)
Total net revenue									$ 25,275,000	$ 25,981,000	$ 15,755,000
Net-revenue concentration (as percent)									8.00%	8.00%	5.00%
Mortgage Banking
Revenue recognition
Net interest income									$ 1,081,000	$ 1,362,000	$ 697,000
Noninterest income:
Mortgage banking income									19,994,000	31,847,000	9,499,000
Total noninterest income									20,185,000	31,950,000	9,712,000
Total net revenue									$ 21,266,000	$ 33,312,000	$ 10,409,000
Net-revenue concentration (as percent)									7.00%	10.00%	3.00%
Republic Processing Group
Revenue recognition
Net interest income									$ 37,046,000	$ 45,615,000	$ 51,552,000
Noninterest income:
Program fees									14,521,000	7,095,000	4,712,000
Total noninterest income									35,125,000	27,675,000	26,789,000
Total net revenue									$ 72,171,000	$ 73,290,000	$ 78,341,000
Net-revenue concentration (as percent)									24.00%	23.00%	25.00%
Tax Refund Solutions
Revenue recognition
Net interest income									$ 15,837,000	$ 22,972,000	$ 21,626,000
Noninterest income:
Program fees									3,171,000	2,193,000	437,000
Total noninterest income									23,775,000	22,773,000	21,855,000
Total net revenue									$ 39,612,000	$ 45,745,000	$ 43,481,000
Net-revenue concentration (as percent)									13.00%	14.00%	14.00%
Republic Credit Solutions
Revenue recognition
Net interest income									$ 21,209,000	$ 22,643,000	$ 29,926,000
Noninterest income:
Program fees									11,350,000	4,902,000	4,275,000
Total noninterest income									11,350,000	4,902,000	4,934,000
Total net revenue									$ 32,559,000	$ 27,545,000	$ 34,860,000
Net-revenue concentration (as percent)									11.00%	9.00%	11.00%
Service charges on deposit accounts
Noninterest income:
Revenue under 606									$ 12,553,000	$ 11,615,000	$ 14,197,000
Service charges on deposit accounts | Core Banking Activities
Noninterest income:
Revenue under 606									12,563,000	11,634,000	14,197,000
Service charges on deposit accounts | Traditional Banking
Noninterest income:
Revenue under 606									12,506,000	11,571,000	14,153,000
Service charges on deposit accounts | Warehouse Lending
Noninterest income:
Revenue under 606									57,000	63,000	44,000
Service charges on deposit accounts | Republic Processing Group
Noninterest income:
Revenue under 606									(10,000)	(19,000)
Service charges on deposit accounts | Tax Refund Solutions
Noninterest income:
Revenue under 606									(10,000)	(19,000)
Net refund transfer fees
Noninterest income:
Revenue under 606									20,248,000	20,297,000	21,158,000
Net refund transfer fees | Republic Processing Group
Noninterest income:
Revenue under 606									20,248,000	20,297,000	21,158,000
Net refund transfer fees | Tax Refund Solutions
Noninterest income:
Revenue under 606									20,248,000	20,297,000	21,158,000
Interchange fee income
Noninterest income:
Revenue under 606									13,062,000	11,188,000	11,859,000
Interchange fee income | Core Banking Activities
Noninterest income:
Revenue under 606									12,777,000	10,978,000	11,600,000
Interchange fee income | Traditional Banking
Noninterest income:
Revenue under 606									12,777,000	10,978,000	11,600,000
Interchange fee income | Republic Processing Group
Noninterest income:
Revenue under 606									285,000	210,000	259,000
Interchange fee income | Tax Refund Solutions
Noninterest income:
Revenue under 606									285,000	210,000	259,000
Net gains (losses) on other real estate owned
Noninterest income:
Revenue under 606									(160,000)	(40,000)	540,000
Net gains (losses) on other real estate owned | Core Banking Activities
Noninterest income:
Revenue under 606									(160,000)	(40,000)	540,000
Net gains (losses) on other real estate owned | Traditional Banking
Noninterest income:
Revenue under 606									(160,000)	(40,000)	540,000
Other
Noninterest income:
Revenue under 606									3,420,000	3,466,000	3,664,000
Other | Core Banking Activities
Noninterest income:
Revenue under 606									3,339,000	3,374,000	3,004,000
Other | Traditional Banking
Noninterest income:
Revenue under 606									3,148,000	3,310,000	2,881,000
Other | Warehouse Lending
Noninterest income:
Revenue under 606										(39,000)	(90,000)
Other | Mortgage Banking
Noninterest income:
Revenue under 606									191,000	103,000	213,000
Other | Republic Processing Group
Noninterest income:
Revenue under 606									81,000	92,000	660,000
Other | Tax Refund Solutions
Noninterest income:
Revenue under 606									$ 81,000	$ 92,000	1,000
Other | Republic Credit Solutions
Noninterest income:
Revenue under 606											$ 659,000