Long-Term Debt - Additional Information (Detail) - USD ($)		9 Months Ended
		Sep. 30, 2017	Dec. 31, 2016
Debt Disclosure [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 200,000,000
Debt Issuance Costs, Line of Credit Arrangements, Gross		1,700,000
Write off of Deferred Debt Issuance Cost		800,000
Long-term Line of Credit	[1]	$ 57,000,000	$ 25,000,000
Debt Instrument, Discounted Percentage		98.00%
Interest Coverage Ratio, Maximum		3.00
Current Ratio		1.00
Second Lien Facility		$ 200,000,000	0
Proceeds from Debt, Net of Issuance Costs		188,100,000
Debt Instrument, Unamortized Discount		4,000,000	0
Unamortized Debt Issuance Expense		$ 7,945,000	0
Year 2 [Member]
Debt Disclosure [Line Items]
Prepayment Premium		102.00%
Prepayment Premium, Change in Control		102.00%
Year 3 [Member]
Debt Disclosure [Line Items]
Prepayment Premium		101.00%
Prepayment Premium, Change in Control		101.00%
Revolving Credit Facility
Debt Disclosure [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 237,500,000
Interest Rate at Period End		4.4163%
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
Second Lien Facility [Member]
Debt Disclosure [Line Items]
Interest rate option one, applicable margin rate over Adjusted LIBOR		7.00%
Interest rate option two, applicable margin rate		6.00%
Second Lien Facility, Initial Interest Rate		8.34%
Second Lien Facility, Effective Interest Rate		9.86%
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%
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%
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

[1] 2 Issuance costs of the Credit Facility, which represent costs attributable to the access to credit over it’s contractual term, have been presented as a component of Other assets (see Note 11) and are being amortized over the term of the Credit Facility using the straight-line method.