EQUITY (Details) $ / shares in Units, $ in Thousands										1 Months Ended	3 Months Ended	12 Months Ended
	Aug. 03, 2015 USD ($) $ / shares shares	Jun. 04, 2015 USD ($) $ / shares shares	Apr. 01, 2015 USD ($) $ / shares shares	Apr. 07, 2014 USD ($) shares	Mar. 21, 2014 $ / shares shares	Feb. 21, 2014 USD ($) $ / shares	Feb. 20, 2014 USD ($) shares	Jan. 29, 2014	Nov. 23, 2010 $ / shares	Dec. 31, 2015 USD ($) $ / shares shares	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares	Dec. 31, 2013 USD ($)	Jan. 31, 2015 USD ($)	May. 20, 2014 USD ($)
EQUITY
Non-cash increase in net income available to common shareholders due to TARP Exchange												$ 0	$ 0	$ 1,895
Decrease in fair value recorded in noninterest income												2,104	3,547	3,249
Other noninterest expense												$ 17,342	$ 18,886	$ 17,927
For ownership change to occur, the minimum cumulative increase in the entity's ownership by "5-percent shareholders" over a rolling three-year period (as a percent)												50.00%
Number of shares repurchased or acquired through tender offer | shares												4,122,881	7,045,620
Common stock, outstanding shares | shares										31,361,452		31,361,452	35,233,674
Common stock, par value (in dollars per share) | $ / shares										$ 0		$ 0	$ 0
Rights
EQUITY
Additional extension period of Tax Benefits Preservation Plan								2 years
Central Bank
EQUITY
Retained earnings													$ 63,700
Common Stock
EQUITY
Number of shares repurchased | shares													857,554
Amount authorized under the 2014 Repurchase Plan																$ 30,000
Repurchased amount													$ 16,500
Common Stock | Repurchase Agreements
EQUITY
Value of shares repurchased or acquired through tender offer				$ 125,000
Tender offer price (in dollars per share) | $ / shares					$ 20.20
Number of shares of common stock properly tendered and not withdrawn at or below the purchase price | shares					3,369,850
Number of shares of common stock tendered through notice of guaranteed delivery at or below the purchase price | shares					167,572
Number of shares repurchased or acquired through tender offer | shares				6,188,066	3,405,888
Share repurchase percentage of common stock properly tendered and not withdrawn at or below the purchase price					96.60%
Share repurchase percentage of issued and outstanding shares of common stock prior to the completion of the tender offer and the private repurchases				14.70%
Common stock, outstanding shares | shares				35,900,000
Number of shares repurchased | shares												4,122,881
Amount authorized under the 2014 Repurchase Plan															$ 75,000
Repurchased amount												$ 93,300
Remaining amount available for repurchase										$ 20,200		$ 20,200
Increase in authorized amount										$ 25,000
Common Stock | Repurchase Agreements | Lead Investors
EQUITY
Value of shares repurchased or acquired through tender offer							$ 56,200
Percentage of shares of common stock held by investors							44.90%
Common Stock | Repurchase Agreements | Carlyle
EQUITY
Value of shares repurchased or acquired through tender offer							$ 28,100
Number of shares repurchased or acquired through tender offer | shares							1,391,089
Number of shares of common stock held by investors | shares							9,463,095
Percentage of shares of common stock held by investors							22.50%
Common Stock | Repurchase Agreements | Anchorage
EQUITY
Number of shares repurchased or acquired through tender offer | shares							1,391,089
Number of shares of common stock held by investors | shares							9,463,095
Percentage of shares of common stock held by investors							22.50%
Common Stock | Underwriting Agreement
EQUITY
Other noninterest expense			$ 400								$ 300
Equity related expense			200
Value of shares repurchased or acquired through tender offer	$ 122,500	$ 66,500	$ 175,000
Common stock, par value (in dollars per share) | $ / shares		$ 0	$ 0
Share Price | $ / shares	$ 22.11	$ 22.15	$ 23.01
Common Stock | Underwriting Agreement | Carlyle
EQUITY
Number of shares repurchased or acquired through tender offer | shares		1,500,000	3,802,694
Common Stock | Underwriting Agreement | Anchorage
EQUITY
Number of shares repurchased or acquired through tender offer | shares		1,500,000	3,802,694
Common Stock | Underwriting Agreement | Carlyle And Anchorage
EQUITY
Number of shares repurchased or acquired through tender offer | shares		3,000,000	7,605,388
Common Stock | Underwriting Agreement | Citigroup Global Markets
EQUITY
Value of shares repurchased or acquired through tender offer			$ 75,000
Number of shares repurchased or acquired through tender offer | shares			3,259,452
Share Price | $ / shares			$ 23.01
Common Stock | Underwriting Agreement | UBS Investment Bank
EQUITY
Number of shares repurchased or acquired through tender offer | shares	5,538,624
Common Stock | Minimum | Repurchase Agreements
EQUITY
Tender offer price (in dollars per share) | $ / shares						$ 18.50
Common Stock | Maximum | Repurchase Agreements
EQUITY
Value of shares repurchased or acquired through tender offer						$ 68,800
Tender offer price (in dollars per share) | $ / shares						$ 21.00
Common Stock | Maximum | Repurchase Agreements | Anchorage
EQUITY
Value of shares repurchased or acquired through tender offer							$ 28,100
Junior Participating Preferred Stock, Series C | Rights
EQUITY
Exercise price of warrant (in dollars per share) | $ / shares									$ 6.00
Fraction of securities callable by each warrant or right									0.0001