SEGMENT INFORMATION (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($) segment	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($)
Segment Disclosure information
Number of operating segments | segment	4
Segment information
Net interest income	$ 56,438	$ 39,434
Provision for loan and lease losses	12,351	5,186
Net refund transfer fees	15,382	17,078
Mortgage banking income	1,160	1,261
Program fees	1,091	319
Other noninterest income	7,290	6,263
Total noninterest income	24,923	24,921
Total noninterest expenses	38,939	32,541
Income before income tax expense	30,071	26,628
Income tax expense	10,054	8,893
NET INCOME	20,017	17,735
Segment end of period total assets	$ 4,664,792	$ 4,246,765	$ 4,816,309
Net interest margin (as percent)	4.99%	3.78%
Core Banking Activities
Segment Disclosure information
Number of operating segments | segment	3
Segment information
Net interest income	$ 36,628	$ 31,295
Provision for loan and lease losses	241	498
Mortgage banking income	1,160	1,261
Other noninterest income	6,540	6,207
Total noninterest income	7,700	7,468
Total noninterest expenses	32,082	26,810
Income before income tax expense	12,005	11,455
Income tax expense	3,498	3,387
NET INCOME	8,507	8,068
Segment end of period total assets	$ 4,525,380	$ 4,117,812
Net interest margin (as percent)	3.33%	3.12%
Traditional Banking
Segment information
Net interest income	$ 32,661	$ 28,608
Provision for loan and lease losses	467	480
Other noninterest income	6,521	6,110
Total noninterest income	6,521	6,110
Total noninterest expenses	30,090	24,875
Income before income tax expense	8,625	9,363
Income tax expense	2,262	2,613
NET INCOME	6,363	6,750
Segment end of period total assets	$ 4,017,173	$ 3,711,315
Net interest margin (as percent)	3.30%	3.08%
Warehouse Lending
Segment information
Net interest income	$ 3,900	$ 2,655
Provision for loan and lease losses	(226)	18
Other noninterest income	6	5
Total noninterest income	6	5
Total noninterest expenses	777	695
Income before income tax expense	3,355	1,947
Income tax expense	1,227	723
NET INCOME	2,128	1,224
Segment end of period total assets	$ 493,127	$ 393,532
Net interest margin (as percent)	3.57%	3.63%
Mortgage Banking
Segment information
Net interest income	$ 67	$ 32
Mortgage banking income	1,160	1,261
Other noninterest income	13	92
Total noninterest income	1,173	1,353
Total noninterest expenses	1,215	1,240
Income before income tax expense	25	145
Income tax expense	9	51
NET INCOME	16	94
Segment end of period total assets	15,080	12,965
Republic Processing Group
Segment information
Net interest income	19,810	8,139
Provision for loan and lease losses	12,110	4,688
Net refund transfer fees	15,382	17,078
Program fees	1,091	319
Other noninterest income	750	56
Total noninterest income	17,223	17,453
Total noninterest expenses	6,857	5,731
Income before income tax expense	18,066	15,173
Income tax expense	6,556	5,506
NET INCOME	11,510	9,667
Segment end of period total assets	$ 139,412	$ 128,953