Investments in Joint Ventures - EnviroFlight - Additional Information (Details) - USD ($)	1 Months Ended				12 Months Ended			47 Months Ended
	Oct. 31, 2016	Feb. 29, 2016	Jan. 31, 2014	Oct. 31, 2013	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017
Schedule Of Investments In Joint Venture [Line Items]
Cash paid in asset acquisition					$ 14,219,000	$ 7,244,000	$ 0
Shares issued in asset acquisition					0	4,401,000	0
Contingent consideration assumed in asset acquisition					0	3,660,000	0
Shares issued as payment for contingent consideration					0	1,583,000	0
Investment					18,870,000	23,655,000		$ 18,870,000
S & I Ophthalmic, LLC
Schedule Of Investments In Joint Venture [Line Items]
Capital contribution				$ 5,000,000			5,000,000
Membership interest				50.00%
OvaXon, LLC
Schedule Of Investments In Joint Venture [Line Items]
Capital contribution			$ 1,500,000					4,350,000
Membership interest			50.00%
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
Additional capital contributions committed, remaining commitment					250,000			250,000
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 | S & I Ophthalmic, LLC
Schedule Of Investments In Joint Venture [Line Items]
Capital contribution				$ 5,000,000			$ 5,000,000
Membership interest				50.00%
Investor | OvaXon, LLC
Schedule Of Investments In Joint Venture [Line Items]
Capital contribution			$ 1,500,000					4,350,000
Membership interest			50.00%
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
Investments in affiliates | S & I Ophthalmic, LLC
Schedule Of Investments In Joint Venture [Line Items]
Investment						3,236,000
Investments in affiliates | OvaXon, LLC
Schedule Of Investments In Joint Venture [Line Items]
Investment					146,000	65,000		146,000
Investments in affiliates | EnviroFlight, LLC
Schedule Of Investments In Joint Venture [Line Items]
Investment					$ 7,092,000	$ 4,189,000		$ 7,092,000