Annual report pursuant to Section 13 and 15(d)

Equity-Based Compensation - Summary of Equity Grants (Detail)

v3.3.1.900
Equity-Based Compensation - Summary of Equity Grants (Detail) - $ / shares
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Performance Units        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Beginning Balance, Units 96,971 238,371 257,757  
Vested, Units (90,585) (140,549)    
Forfeited, Units   (851) (19,386)  
Ending Balance, Units 6,386 96,971 238,371  
Fair Value per unit $ 3.75 $ 3.75 $ 3.75 $ 3.27
Vested, Range of Fair Value per unit $ (3.75) $ (3.75)    
Forfeited, Range of Fair Value per unit     $ (3.75)  
Deferred Compensation Share Based Payments        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Beginning Balance, Units 52,188 175,298 329,757  
Vested, Units (47,277) (123,110) (150,398)  
Forfeited, Units     (4,066)  
Ending Balance, Units 4,911 52,188 175,298  
Deferred Compensation Share Based Payments | Minimum        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Fair Value per unit $ 12.00 $ 12.00 $ 12.00  
Vested, Range of Fair Value per unit (12.00) (12.00)    
Deferred Compensation Share Based Payments | Maximum        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Fair Value per unit 11.89 15.65 17.05 $ 10.47
Vested, Range of Fair Value per unit $ (13.97) $ (16.81) (17.05)  
Forfeited, Range of Fair Value per unit     $ (17.05)