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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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Amount of cash restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits.

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Summary of Significant Accounting Policies - Narrative (Details) $ in Thousands		3 Months Ended		9 Months Ended
	May 28, 2020 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)	Jan. 31, 2019 USD ($)
Summary of Significant Accounting Policies Details [Line Items]
Reverse stock split, conversion ratio	0.10
Derivative liability	$ 6,300	$ 5,600		$ 5,600
Revenue, net		44,264	$ 41,814	104,147	$ 108,550
Assets		190,254		190,254		$ 206,905
Convertible Note 2019
Summary of Significant Accounting Policies Details [Line Items]
Restricted cash							$ 2,700
Domestic
Summary of Significant Accounting Policies Details [Line Items]
Revenue, net		12,700	13,400	27,800	36,500
Assets		147,900	142,500	147,900	142,500
Foreign
Summary of Significant Accounting Policies Details [Line Items]
Revenue, net		1,600	5,100	7,600	13,400
Assets		$ 42,400	$ 53,700	$ 42,400	$ 53,700
Sales Revenue
Summary of Significant Accounting Policies Details [Line Items]
Concentration risk		47.00%	47.00%	34.00%	48.00%
Sales Revenue \| Customer One
Summary of Significant Accounting Policies Details [Line Items]
Concentration risk		21.00%	35.00%	22.00%	29.00%
Sales Revenue \| Customer Two
Summary of Significant Accounting Policies Details [Line Items]
Concentration risk		13.00%	12.00%	12.00%	19.00%
Sales Revenue \| Customer Three
Summary of Significant Accounting Policies Details [Line Items]
Concentration risk		13.00%
Accounts Receivable
Summary of Significant Accounting Policies Details [Line Items]
Concentration risk				46.00%	47.00%
Fair Value \| Series C Senior Convertible Notes due 2023
Summary of Significant Accounting Policies Details [Line Items]
Debt instrument, fair value disclosure		$ 27,531		$ 27,531
Fair Value \| Series D Senior Convertible Notes
Summary of Significant Accounting Policies Details [Line Items]
Debt instrument, fair value disclosure		10,500		10,500
Book Value \| Series C Senior Convertible Notes due 2023
Summary of Significant Accounting Policies Details [Line Items]
Debt instrument, fair value disclosure		30,992		30,992
Book Value \| Series D Senior Convertible Notes
Summary of Significant Accounting Policies Details [Line Items]
Debt instrument, fair value disclosure		$ 47,419		$ 47,419