Long-Term Debt - Additional Information (Detail) - USD ($)		3 Months Ended		9 Months Ended
	Mar. 11, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Debt Instrument [Line Items]
Interest expense		$ 1,500,000	$ 505,000	$ 4,000,000	$ 1,400,000
Interest paid		2,400,000	538,000	3,900,000	1,400,000
First semi annual interest payment		1,700,000
Interest capitalized		0	0	0	11,000
Loan Cost Amortization		98,000	64,000	265,443	173,965
Amortization of discount		$ 265,000	$ 0	$ 583,152	$ 0
4.50% Convertible Senior Notes due 2020 [Member]
Debt Instrument [Line Items]
Debt discount	$ 6,100,000