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Derivative Financial Instruments - Additional Information (Detail) - USD ($)
3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2017
Jun. 30, 2017
Jun. 30, 2018
Apr. 17, 2017
Dec. 31, 2016
Jun. 24, 2016
Derivative Instruments Gain Loss [Line Items]            
Derivative, notional amount $ 350,000,000 $ 350,000,000     $ 350,000,000  
Derivative, strike rate for the interest rate swap contract       1.1325%   1.145%
Realized (gains) losses on interest rate hedges reclassified to earnings 51,000 183,000        
Interest Rate Swap            
Derivative Instruments Gain Loss [Line Items]            
Derivative, notional amount 150,000,000 $ 150,000,000       $ 150,000
Derivative, maturity date   Jun. 17, 2021        
Recognition of hedge ineffectiveness (12,000)          
Interest Rate Swap | Cash Flow Hedge            
Derivative Instruments Gain Loss [Line Items]            
Derivative, notional amount $ 150,000,000 $ 150,000,000     $ 150,000,000  
Interest Rate Swaps and Caps | Scenario, Forecast | Cash Flow Hedge            
Derivative Instruments Gain Loss [Line Items]            
Reclassified out of accumulated other comprehensive income to earnings, amount     $ 315,000