Commitments and Contingencies - Other (Details)		1 Months Ended	3 Months Ended		6 Months Ended
	Mar. 18, 2019 item	Aug. 31, 2018 item	Jun. 30, 2020 USD ($) item	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) item	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Other commitments
Letter of Credit outstanding			$ 8,800,000		$ 8,800,000
Restricted cash pledged for letter of credit			$ 8,800,000	$ 8,800,000	$ 8,800,000	$ 8,800,000
Number of Months from start of lease for adjustments to Letter of Credit | item			37		37
Frequency of adjustment to Letter of Credit					12 months
Adjustment rate of Letter of Credit (as a percent)					20.00%
Amount of Letter of Credit outstanding after adjustments			$ 2,000,000.0		$ 2,000,000.0
Number of other irrevocable letters of credit outstanding | item			2		2
Restricted cash pledged for office lease agreement			$ 400,000		$ 400,000
Restricted cash pledged for credit card program			200,000		200,000
Purchase commitment obligation			5,400,000		5,400,000
Deferred compensation plan liability			4,100,000		4,100,000		$ 3,700,000
Deferred compensation plan assets			4,200,000		4,200,000		$ 3,500,000
Agreement with the Regents
Other commitments
Minimum required annual payment of the commitment obligation, based on net sales of current and future products			500,000		500,000
Maximum | Buyout Agreement with GMP Vision Solutions, Inc.
Other commitments
Buyout amount upon sale of Company.			2,000,000.0		2,000,000.0
Cost of sales | Agreement with the Regents
Other commitments
Commitment obligation payments			600,000	$ 1,500,000	$ 1,700,000	$ 2,800,000
Patent Litigation | Pending Litigation
Other commitments
Number of patent infringements | item		3
Number of new new petitions filed | item	5
Number of claims on summary judgement granted | item					1
Securities Litigation | Pending Litigation
Other commitments
Accrual for loss contingency			$ 0		$ 0