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STOCKHOLDERS' EQUITY - Exchange offer with respect to Series A through E preferred stock (Detail) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended 12 Months Ended
Jun. 30, 2015
Dec. 31, 2017
Dec. 31, 2016
Class Of Stock [Line Items]      
Liquidation value per share   $ 25  
Preferred stock, shares outstanding   1,444,146 1,444,146
Preferred Stock Value   $ 36,104 $ 36,104
Shares of common stock issued 852,831    
7.125% Noncumulative Perpetual Monthly Income Preferred Stock, Series A [Member]      
Class Of Stock [Line Items]      
Preferred stock dividend rate percentage   7.125%  
8.35% Noncumulative Perpetual Monthly Income Preferred Stock, Series B [Member]      
Class Of Stock [Line Items]      
Preferred stock dividend rate percentage   8.35%  
7.40% Noncumulative Perpetual Monthly Income Preferred Stock, Series C [Member]      
Class Of Stock [Line Items]      
Preferred stock dividend rate percentage   7.40%  
7.25% Noncumulative Perpetual Monthly Income Preferred Stock, Series D [Member]      
Class Of Stock [Line Items]      
Preferred stock dividend rate percentage   7.25%  
7.00% Noncumulative Perpetual Monthly Income Preferred Stock, Series E [Member]      
Class Of Stock [Line Items]      
Preferred stock dividend rate percentage   7.00%