Quarterly report pursuant to Section 13 or 15(d)

Long-term Debt - Additional Information (Detail)

v3.8.0.1
Long-term Debt - Additional Information (Detail) - USD ($)
Mar. 31, 2018
Feb. 14, 2018
Dec. 31, 2017
Jan. 26, 2015
Jan. 22, 2014
Jul. 30, 2013
Debt Instrument [Line Items]            
Deferred acquisition costs $ 6,596,000   $ 7,029,000      
2015 Secured Credit Agreement            
Debt Instrument [Line Items]            
Deferred acquisition costs 1,100,000          
Maximum borrowing capacity   $ 80,000,000 $ 100,000,000 $ 200,000,000    
Minimum liquidity amount   30,000,000        
Minimum liquidity amount, restricted amount 15,000,000 15,000,000        
Maximum borrowing capacity net of restricted liquidity amount and outstanding letters of credit   $ 65,000,000        
Unamortized debt issuance expense 1,600,000          
Senior secured credit facility 72,600,000          
Letters of credit outstanding 5,700,000          
Remaining borrowing capacity 51,900,000          
Long-term line of credit 0          
6.75% Senior Notes, due July 2022            
Debt Instrument [Line Items]            
Percentage of notes guaranteed by restricted subsidiaries         6.75%  
Aggregate principal amount         $ 360,000,000  
Debt issuance costs 7,600,000          
Deferred acquisition costs $ 4,400,000          
Redemption price after year three 103.375%          
Redemption price after year five         101.00%  
7.50% Senior Notes, due August 2020            
Debt Instrument [Line Items]            
Percentage of notes guaranteed by restricted subsidiaries           7.50%
Aggregate principal amount           $ 225,000,000
Debt issuance costs $ 5,600,000          
Deferred acquisition costs $ 2,200,000          
Redemption price after year three 101.875%          
Redemption price after year five           101.00%