Debt - Equipment Credit Facility - Additional Information (Detail) - Comerica syndicated credit facility, $60 million equipment financing facility [Member]	12 Months Ended
	Dec. 31, 2015 Installment Option	Dec. 31, 2014
Line of Credit Facility [Line Items]
Credit facility, expiration date	Aug. 28, 2015
Frequency of installments	Quarterly
Number of installments | Installment	28
Number of interest rate options | Option	2
Credit facility fees percentage	0.50%
Interest accrued percentage		2.52%
Eurodollar-based [Member]
Line of Credit Facility [Line Items]
Line of credit facility, interest rate description	Eurodollar-based advances bear interest at 30, 60 or 90-day LIBOR rates plus an applicable margin, which varied from 1.60% to 2.60% based on our ratio of total debt to EBITDA.
Eurodollar-based [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Interest rate above variable base rate	1.60%
Eurodollar-based [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Interest rate above variable base rate	2.60%
Base rate [Member]
Line of Credit Facility [Line Items]
Line of credit facility, interest rate description	Base rate advances bore interest at a base rate, as defined, plus an applicable margin, which also varied based on our ratio of total debt to EBITDA in a range from 0.60% to 1.60%.
Base rate [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Interest rate above variable base rate	0.60%
Base rate [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Interest rate above variable base rate	1.60%