Debt - Margin for Borrowings under Revolving Credit Facility (Detail)	12 Months Ended
	Dec. 31, 2016 USD ($)
Revolving Credit Facility
Debt Instrument [Line Items]
Availability of borrowing	$ 37,500,000
Level III | Revolving Credit Facility | Minimum
Debt Instrument [Line Items]
Availability of borrowing	$ 20,000,000
Level III | Domestic Base Rate Loans
Debt Instrument [Line Items]
Loans Rate	0.50%
Level III | LIBOR Revolver Loans
Debt Instrument [Line Items]
Loans Rate	1.50%
Level II | Revolving Credit Facility | Minimum
Debt Instrument [Line Items]
Availability of borrowing	$ 10,000,000
Level II | Revolving Credit Facility | Maximum
Debt Instrument [Line Items]
Availability of borrowing	$ 20,000,000
Level II | Domestic Base Rate Loans
Debt Instrument [Line Items]
Loans Rate	0.75%
Level II | LIBOR Revolver Loans
Debt Instrument [Line Items]
Loans Rate	1.75%
Level I | Revolving Credit Facility | Maximum
Debt Instrument [Line Items]
Availability of borrowing	$ 10,000,000
Level I | Domestic Base Rate Loans
Debt Instrument [Line Items]
Loans Rate	1.00%
Level I | LIBOR Revolver Loans
Debt Instrument [Line Items]
Loans Rate	2.00%