Long-Term Debt - Additional Information (Detail) - USD ($)		3 Months Ended		9 Months Ended
	Mar. 11, 2015	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Debt Instrument [Line Items]
Interest expense		$ 1,700,000	$ 1,500,000	$ 5,200,000	$ 4,000,000
Interest paid		2,600,000	2,400,000	6,000,000	3,900,000
Interest capitalized			0	0	0
Loan Cost Amortization		488,000	98,000	715,448	265,443
Amortization of Discount on Convertible Debt		282,000	$ 265,000	833,903	$ 583,152
Write off of unamortized loan costs		367,000
Line of credit facility, current borrowing capacity		$ 75,000,000		$ 75,000,000
4.50% Convertible Senior Notes due 2020 [Member]
Debt Instrument [Line Items]
Debt discount	$ 6,100,000