Investments in Joint Ventures - EnviroFlight - Additional Information (Details) - USD ($)	1 Months Ended		6 Months Ended
	Oct. 31, 2016	Feb. 29, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Cash paid in asset acquisition			$ 14,219,000	$ 7,244,000
Shares issued in asset acquisition			0	4,401,000
Contingent consideration assumed in asset acquisition			0	$ 3,660,000
Shares issued as payment of deferred consideration			0
Investment			21,904,000		$ 23,655,000
Significant Unobservable Inputs (Level 3)
Schedule of Equity Method Investments [Line Items]
Fair value of financial liabilities measured at fair value on a recurring basis			2,826,000		2,081,000
EnviroFlight, LLC
Schedule of Equity Method Investments [Line Items]
Cash paid in asset acquisition		$ 4,244,000
Shares issued in asset acquisition (in shares)		136,340
Shares issued in asset acquisition		$ 4,401,000
Contingent consideration assumed in asset acquisition		3,660,000
Capital contributions		$ 3,000,000
Membership interest		50.00%
Maximum additional capital contribution committed		$ 5,000,000
Additional capital contributions committed, remaining commitment			2,750,000
Estimated fair value of investment		5,425,000
Shares issued for contingent consideration (in shares)	59,337
Shares issued as payment of deferred consideration	$ 1,583,000
Contingent consideration for commercial milestones payable in common stock, maximum		4,000,000
EnviroFlight, LLC | Investments In Affiliates
Schedule of Equity Method Investments [Line Items]
Investment			5,673,000		$ 4,189,000
EnviroFlight, LLC | Significant Unobservable Inputs (Level 3)
Schedule of Equity Method Investments [Line Items]
Fair value of financial liabilities measured at fair value on a recurring basis			$ 2,241,000
EnviroFlight, LLC | Patents, developed technologies and know-how
Schedule of Equity Method Investments [Line Items]
Estimated fair value of developed technology acquired		$ 9,880,000
Expected useful life of intangible asset		21 years
EnviroFlight, LLC | Investors
Schedule of Equity Method Investments [Line Items]
Membership interest		50.00%
Maximum additional capital contribution committed		$ 5,000,000