| PARENT COMPANY FINANCIAL INFORMATION (Tables)
 | 12 Months Ended | 
      
        | Dec. 31, 2014 | 
      
        | Condensed Financial Information of Parent Company Only Disclosure [Abstract] |  | 
      
        | Condensed Balance Sheets |    CONDENSED BALANCE SHEETS (In Thousands)    |   |   | December31, 2014
 |   | December 31,2013
 |   |   | ASSETS |   |   |   |   |   |   |   |   | Cash and due from banks |   | $ | 61,611 |   | $ | 2,562 |   |   | Investment in subsidiary |   |   | 366,609 |   |   | 314,489 |   |   | Other assets |   |   | 51 |   |   | 194 |   |   | Total assets |   | $ | 428,271 |   | $ | 317,245 |   |   |   |   |   |   |   |   |   |   |   | LIABILITIES AND STOCKHOLDERS' EQUITY |   |   |   |   |   |   |   |   | Liabilities: |   |   |   |   |   |   |   |   | Other borrowings |   | $ | 19,973 |   | $ | 19,940 |   |   | Other liabilities |   |   | 1,337 |   |   | 113 |   |   | Total liabilities |   |   | 21,310 |   |   | 20,053 |   |   | Stockholders' equity: |   |   |   |   |   |   |   |   |  Preferred stock, Series A Senior Non-Cumulative Perpetual, par value $.001 (liquidation preference $1,000), net of discount; 40,000 shares authorized, 40,000 shares issued and outstanding at December 31, 2014 and 2013 |   |   | 39,958 |   |   | 39,958 |   |   | Common stock, par value $.001 per share; 50,000,000 shares authorized; 24,801,518 shares issued and outstanding at December 31, 2014 and 22,050,036 shares issued and outstanding at December 31, 2013 |   |   | 25 |   |   | 7 |   |   | Additional paid-in capital |   |   | 185,397 |   |   | 123,325 |   |   | Retained earnings |   |   | 177,091 |   |   | 130,011 |   |   | Accumulated other comprehensive income |   |   | 4,490 |   |   | 3,891 |   |   | Total stockholders' equity |   |   | 406,961 |   |   | 297,192 |   |   | Total liabilites and stockholders' equity |   | $ | 428,271 |   | $ | 317,245 |   |  | 
      
        | Condensed Statements of Income |    CONDENSED STATEMENTS OF INCOME FOR THE YEARS ENDED DECEMBER 31, (In Thousands)    |   |   | 2014 |   | 2013 |   | 2012 |   |   | Income: |   |   |   |   |   |   |   |   |   |   |   | Dividends received from subsidiary |   | $ | 12,000 |   | $ | 4,750 |   | $ | - |   |   | Other income |   |   | - |   |   | 1 |   |   | 41 |   |   | Total income |   |   | 12,000 |   |   | 4,751 |   |   | 41 |   |   | Expense: |   |   |   |   |   |   |   |   |   |   |   | Other expenses |   |   | 1,183 |   |   | 1,147 |   |   | 1,594 |   |   | Total expenses |   |   | 1,183 |   |   | 1,147 |   |   | 1,594 |   |   | Equity in undistributed earnings of subsidiary |   |   | 41,529 |   |   | 37,997 |   |   | 35,998 |   |   | Net income |   |   | 52,346 |   |   | 41,601 |   |   | 34,445 |   |   | Dividends on preferred stock |   |   | 400 |   |   | 400 |   |   | 400 |   |   | Net income available to common stockholders |   |   | 51,946 |   |   | 41,201 |   |   | 34,045 |   |  | 
      
        | Statement of Cash Flows |    STATEMENTS OF CASH FLOW FOR THE YEARS ENDED DECEMBER 31, (In Thousands)    |   |   | 2014 |   | 2013 |   | 2012 |   |   | Operating activities |   |   |   |   |   |   |   |   |   |   |   | Net income |   | $ | 52,346 |   | $ | 41,601 |   | $ | 34,445 |   |   | Adjustments to reconcile net income to net cash used in operating activities: |   |   |   |   |   |   |   |   |   |   |   | Other |   |   | 165 |   |   | (224) |   |   | 878 |   |   | Equity in undistributed earnings of subsidiary |   |   | (41,529) |   |   | (37,997) |   |   | (35,998) |   |   | Net cash (used in) provided by operating activities |   |   | 10,982 |   |   | 3,380 |   |   | (675) |   |   | Investing activities |   |   |   |   |   |   |   |   |   |   |   | Investment in subsidiary |   |   | - |   |   | (10,499) |   |   | - |   |   | Net cash used in investing activities |   |   | - |   |   | (10,499) |   |   | - |   |   | Financing activities |   |   |   |   |   |   |   |   |   |   |   | Proceeds from other borrowings |   |   | - |   |   | - |   |   | 19,917 |   |   | Repayment of subordinated debentures |   |   | - |   |   | - |   |   | (15,464) |   |   | Proceeds from issuance of common stock, net |   |   | 52,076 |   |   | 10,499 |   |   | 112 |   |   | Dividends paid on common stock |   |   | (3,609) |   |   | (3,682) |   |   | (3,134) |   |   | Dividends paid on preferred stock |   |   | (400) |   |   | (400) |   |   | (400) |   |   | Net cash provided by financing activities |   |   | 48,067 |   |   | 6,417 |   |   | 1,031 |   |   | Increase (decrease) in cash and cash equivalents |   |   | 59,049 |   |   | (702) |   |   | 356 |   |   | Cash and cash equivalents at beginning of year |   |   | 2,562 |   |   | 3,264 |   |   | 2,908 |   |   | Cash and cash equivalents at end of year |   | $ | 61,611 |   | $ | 2,562 |   | $ | 3,264 |    
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