Quarterly report pursuant to Section 13 or 15(d)

Long-Term Debt - Additional Information (Detail)

v3.7.0.1
Long-Term Debt - Additional Information (Detail) - USD ($)
3 Months Ended
Mar. 31, 2017
Dec. 31, 2016
Debt Disclosure [Line Items]    
Line of Credit Facility, Maximum Borrowing Capacity $ 128,000,000 $ 128,000,000
Long-term Line of Credit $ 30,000,000 25,000,000
Interest Coverage Ratio, Maximum 3.00  
Current Ratio 1.00  
Revolving Credit Facility    
Debt Disclosure [Line Items]    
Line of Credit Facility, Maximum Borrowing Capacity $ 200,000,000  
Interest Rate at Period End 3.915%  
Revolving Credit Facility | Future Period [Member]    
Debt Disclosure [Line Items]    
Debt To E B I T D Ratio Maximum 4.00  
Revolving Credit Facility | Future Period Two [Member]    
Debt Disclosure [Line Items]    
Debt To E B I T D Ratio Maximum 3.75  
Revolving Credit Facility | Future Period Three [Member]    
Debt Disclosure [Line Items]    
Debt To E B I T D Ratio Maximum 3.50  
Letter of Credit    
Debt Disclosure [Line Items]    
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage 0.50%  
Line of Credit [Member]    
Debt Disclosure [Line Items]    
Letters of Credit Outstanding, Amount $ 800,000 $ 800,000
Line of Credit [Member] | Letter of Credit    
Debt Disclosure [Line Items]    
Line of Credit Facility, Maximum Borrowing Capacity $ 5,000,000.0  
Maximum [Member] | Revolving Credit Facility    
Debt Disclosure [Line Items]    
Interest rate option one, applicable margin rate over Adjusted LIBOR 3.00%  
Interest rate option two, applicable margin rate 4.00%  
Minimum [Member] | Revolving Credit Facility    
Debt Disclosure [Line Items]    
Interest rate option one, applicable margin rate over Adjusted LIBOR 2.00%  
Interest rate option two, applicable margin rate 3.00%  
Interest Payable One [Member] | Revolving Credit Facility    
Debt Disclosure [Line Items]    
Debt Instrument, Interest Payable Period 1 month  
Interest Payable Two [Member] | Revolving Credit Facility    
Debt Disclosure [Line Items]    
Debt Instrument, Interest Payable Period 3 months  
Interest Payable Three [Member] | Revolving Credit Facility    
Debt Disclosure [Line Items]    
Debt Instrument, Interest Payable Period 6 months