PARENT COMPANY CONDENSED FINANCIAL INFORMATION - CASH FLOWS (Details) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2015
Sep. 30, 2015
Jun. 30, 2015
Mar. 31, 2015
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
STATEMENTS OF CASH FLOWS                      
Net income $ 10,000 $ 9,828 $ 8,340 $ 17,735 $ 7,418 $ 5,640 $ 8,320 $ 13,788 $ 45,903 $ 35,166 $ 28,787
Adjustments to reconcile net income to net cash provided by operating activities:                      
Accretion of Investment security                 503 729 424
Director deferred compensation - Parent Company                 170 223 187
Change in other assets                 (7,227) (2,785) (2,145)
Change in other liabilities                 540 5,473 (2,570)
Net cash provided by operating activities                 47,672 50,046 26,705
Investing activities:                      
Acquisition of Cornerstone Bancorp, Inc.                 9,088    
Purchases of securities available for sale                 (419,254) (1,512,809) (876,854)
Net cash used in investing activities                 (296,134) (358,208) (470,894)
Financing activities:                      
Payoff of subordinated note, net of common security interest                 (4,000)    
Common Stock repurchases                 (1,207) (551) (347)
Net proceeds from Common Stock options exercised                 80 1,136 1,103
Cash dividends paid                 (16,768) (15,839) (14,930)
Net cash provided by (used in) financing activities                 327,689 445,366 346,204
NET CHANGE IN CASH AND CASH EQUIVALENTS                 79,227 137,204 (97,985)
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR       210,082       72,878 210,082 72,878 170,863
CASH AND CASH EQUIVALENTS AT END OF YEAR 289,309       210,082       289,309 210,082 72,878
Republic Bancorp, Inc.                      
STATEMENTS OF CASH FLOWS                      
Net income                 45,903 35,166 28,787
Adjustments to reconcile net income to net cash provided by operating activities:                      
Accretion of Investment security                 (44) (4)  
Equity in undistributed net income of subsidiaries                 (27,549) (19,512) (13,995)
Director deferred compensation - Parent Company                 103 108 98
Change in other assets                 (1,366) 1,853 3,834
Change in other liabilities                 (313) 201 (1,500)
Net cash provided by operating activities                 16,734 17,812 17,224
Investing activities:                      
Acquisition of Cornerstone Bancorp, Inc.                 31,795    
Investment in Republic Insurance Services, Inc.                     (246)
Purchases of securities available for sale                   (3,401)  
Net cash used in investing activities                 (31,795) (3,401) (246)
Financing activities:                      
Payoff of subordinated note, net of common security interest                 (4,000)    
Common Stock repurchases                 (1,207) (551) (347)
Net proceeds from Common Stock options exercised                 80 1,136 1,103
Cash dividends paid                 (16,768) (15,839) (14,930)
Net cash provided by (used in) financing activities                 (21,895) (15,254) (14,174)
NET CHANGE IN CASH AND CASH EQUIVALENTS                 (36,956) (843) 2,804
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR       $ 132,711       $ 133,554 132,711 133,554  
CASH AND CASH EQUIVALENTS AT END OF YEAR $ 95,755       $ 132,711       $ 95,755 $ 132,711 $ 133,554