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