Summary of Significant Accounting Policies - Narrative (Details) shares in Thousands		1 Months Ended				3 Months Ended		12 Months Ended
	Aug. 02, 2021 USD ($) monthly_installment	Feb. 28, 2021 USD ($)	Mar. 31, 2020 USD ($)	Nov. 30, 2019 USD ($)	Feb. 28, 2014 USD ($)	Dec. 31, 2019 USD ($)	Mar. 31, 2019 USD ($) shares	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($) shares	Sep. 30, 2020 USD ($)	Aug. 02, 2018 USD ($)	Mar. 31, 2018 USD ($)
Schedule Of Significant Accounting Policies [Line Items]
Total revenue								$ 130,581,000	$ 138,144,000	$ 117,243,000
Legal costs			$ 400,000
Product warranty term								1 year
Depreciation								$ 2,800,000	3,100,000	3,600,000
Impairment of goodwill								0	0	0
Impairment of intangible asset								0	0	443,000
Maximum contract value								34,000,000			$ 34,000,000
Number of installments | monthly_installment	24
Term loan advances percentage	6.50%
Loss from extinguishment of debt								9,000	0	12,020,000
Advertising costs incurred								3,400,000	1,600,000	$ 3,400,000
Common Stock
Schedule Of Significant Accounting Policies [Line Items]
Conversion of debt into common stock (in shares) | shares										19,460
Secured Debt
Schedule Of Significant Accounting Policies [Line Items]
Principal amount	$ 10,000,000							$ 10,000,000	0
Number of installments | monthly_installment	24
Term loan advances percentage	6.50%
Interest rate on notes								4.00%
Principal amount								$ 10,000,000	0
Convertible Debt
Schedule Of Significant Accounting Policies [Line Items]
Principal amount								55,578,000	56,079,000
Convertible Debt | 2014 Notes
Schedule Of Significant Accounting Policies [Line Items]
Principal amount					$ 201,300,000			578,000	1,079,000
Interest rate on notes					2.75%
Debt extinguished				$ 50,200,000
Principal amount		$ 500,000						578,000	1,079,000				$ 51,300,000
Convertible Debt | 2014 Notes | Redemption, Period Three
Schedule Of Significant Accounting Policies [Line Items]
Debt instrument redemption price		100.00%			100.00%
Convertible Debt | 2014 Notes | Common Stock
Schedule Of Significant Accounting Policies [Line Items]
Conversion of debt into common stock (in shares) | shares							19,500
Convertible Debt | Exchange Convertible Senior Notes due 2034
Schedule Of Significant Accounting Policies [Line Items]
Borrowing Base							$ 150,000,000						150,000,000
Principal amount													$ 150,000,000
Interest rate on notes													2.75%
Loss from extinguishment of debt		$ 9,000		3,000,000		$ 3,000,000	$ 9,000,000
Debt extinguished				50,200,000
Convertible Debt | Exchange Convertible Senior Notes due 2034 | Common Stock
Schedule Of Significant Accounting Policies [Line Items]
Conversion of debt into common stock (in shares) | shares							19,500
Convertible Debt | 2019 Notes
Schedule Of Significant Accounting Policies [Line Items]
Principal amount				$ 55,000,000				55,000,000	55,000,000
Interest rate on notes				5.25%
Debt extinguished				$ 51,800,000
Principal amount		$ 500,000						$ 55,000,000	55,000,000
Convertible Debt | 2019 Notes | Redemption, Period Three
Schedule Of Significant Accounting Policies [Line Items]
Debt instrument redemption price		100.00%
Revolving Credit Facility
Schedule Of Significant Accounting Policies [Line Items]
Borrowing Base	$ 15,000,000.0											$ 15,000,000
Line of credit facility, term of extension	1 year
Office furniture and fixtures
Schedule Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives								5 years
Intellectual Property Infringement Claims
Schedule Of Significant Accounting Policies [Line Items]
Proceeds from legal settlements			3,500,000
Minimum | Computer equipment and software
Schedule Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives								3 years
Minimum | Laboratory and manufacturing equipment
Schedule Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives								2 years
Maximum | Computer equipment and software
Schedule Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives								4 years
Maximum | Laboratory and manufacturing equipment
Schedule Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives								7 years
Product revenue
Schedule Of Significant Accounting Policies [Line Items]
Total revenue								$ 100,376,000	99,944,000	$ 95,416,000
Product revenue | Minimum
Schedule Of Significant Accounting Policies [Line Items]
Terms of payment period								30 days
Product revenue | Maximum
Schedule Of Significant Accounting Policies [Line Items]
Terms of payment period								60 days
Service revenue
Schedule Of Significant Accounting Policies [Line Items]
Total revenue								$ 25,917,000	22,579,000	21,277,000
Service revenue | Minimum
Schedule Of Significant Accounting Policies [Line Items]
Performance obligation period								1 year
Service revenue | Maximum
Schedule Of Significant Accounting Policies [Line Items]
Performance obligation period								3 years
Other revenue
Schedule Of Significant Accounting Policies [Line Items]
Total revenue			$ 3,100,000					$ 147,000	$ 3,163,000	$ 0