Commitments and Contingencies - Additional Information (Detail) (USD $)	0 Months Ended		12 Months Ended			2 Months Ended
	Oct. 01, 2014 Charge	Aug. 25, 2014 Installment	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	May 31, 2013
Contingencies And Commitments [Line Items]
Financing fees incurred			$ 122,230	$ 1,741,976
Number of misdemeanor charges to which the company pleaded guilty	3
Fine for violation of Clean Water Act	600,000
Period of probation	2 years
Civil penalties per violation		3,000,000
Number of installments for payment of civil penalty		2
Estimated site restoration costs		13,000,000
Oppenheimer & Co., Inc [Member]
Contingencies And Commitments [Line Items]
Financing fees incurred					401,625
Cash [Member]
Contingencies And Commitments [Line Items]
Financing fees incurred					300,000
Common Stock [Member]
Contingencies And Commitments [Line Items]
Financing fees incurred					$ 101,625
Number of shares issued for settlement			37,500		37,500
Common stock issued, par value					$ 2.71
President and chairman of board [Member]
Contingencies And Commitments [Line Items]
Number of shares vested						85,000
Employee [Member]
Contingencies And Commitments [Line Items]
Number of shares vested						50,000