Long-Term Debt - Additional Information (Detail) - USD ($)		12 Months Ended
	Mar. 11, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Interest expense		$ 5,700,000	$ 2,200,000	$ 1,600,000
Interest paid		4,700,000	2,100,000	1,600,000
Interest capitalized		0	11,000	8,000
Loan Cost Amortization		365,860	256,332	202,500
Amortization of Discount on Convertible Debt		$ 852,368	$ 0	$ 0
4.50% Convertible Senior Notes due 2020 [Member]
Debt Instrument [Line Items]
Debt discount	$ 6,100,000