Investments in Joint Ventures - EnviroFlight - Additional Information (Details) - USD ($)	1 Months Ended		12 Months Ended
	Oct. 31, 2016	Feb. 29, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule Of Investments In Joint Venture [Line Items]
Cash paid in asset acquisition			$ 7,244,000	$ 0	$ 0
Shares issued in asset acquisition			4,401,000	0	0
Contingent consideration assumed in asset acquisition			3,660,000	0	0
Shares issued as payment for contingent consideration			1,583,000	0	$ 0
Investment			23,655,000	$ 9,977,000
EnviroFlight, LLC
Schedule Of Investments In Joint Venture [Line Items]
Cash paid in asset acquisition		$ 4,244,000
Shares issued in asset acquisition, shares		136,340
Shares issued in asset acquisition		$ 4,401,000
Contingent consideration assumed in asset acquisition		3,660,000
Capital contribution		$ 3,000,000
Membership interest		50.00%
Maximum additional capital contributions committed		$ 5,000,000
Estimated fair value of investment		5,425,000
Shares issued as payment for contingent consideration, shares	59,337
Shares issued as payment for contingent consideration	$ 1,583,000
Contingent consideration for commercial milestones payable in common stock, maximum		$ 4,000,000
Investor | EnviroFlight, LLC
Schedule Of Investments In Joint Venture [Line Items]
Membership interest		50.00%
Maximum additional capital contributions committed		$ 5,000,000
Patents, developed technologies and know-how | EnviroFlight, LLC
Schedule Of Investments In Joint Venture [Line Items]
Estimated fair value of developed technology acquired		$ 9,880,000
Expected useful life of intangible asset		21 years
Significant Unobservable Inputs (Level 3)
Schedule Of Investments In Joint Venture [Line Items]
Contingent consideration assumed in asset acquisition			3,660,000
Fair value of financial liabilities measured at fair value on a recurring basis			2,081,000
Shares issued as payment for contingent consideration			1,583,000
Significant Unobservable Inputs (Level 3) | EnviroFlight, LLC
Schedule Of Investments In Joint Venture [Line Items]
Fair value of financial liabilities measured at fair value on a recurring basis			2,081,000
Investments in affiliates | EnviroFlight, LLC
Schedule Of Investments In Joint Venture [Line Items]
Investment			$ 4,189,000