Debt (Tables)

6 Months Ended

Jun. 30, 2021

Debt Disclosure [Abstract]

Summary of Debt Obligations

The following table sets forth our various debt obligations:

	June 30, 2021		December 31, 2020
Series A Note (principal amount)	$	—	$	2,481
Series B Note (principal amount)	—		3,585
Paycheck Protection Program Loan	2,850		2,850
Convertible notes	243		250
Promissory notes	905		905
Total debt	$	3,998	$	10,071
Debt discount - warrants (2020 Convertible Notes)	—		(1,029)
Debt discount - issuance costs (2020 Convertible Notes)	—		(650)
Less: current maturities of long-term debt	(83)		(4,435)
Less: related-party debt	(195)		(195)
Long-term debt	$	3,720	$	3,762

Summary of Calculated Aggregate Fair Values and Assumptions

The following table sets forth the assumptions used to calculate the fair value of our warrant liability at the respective dates:

	June 30, 2021			December 31, 2020
Strike price per share	$	2.25		$	4.00
Closing price per share	$	1.39		$	1.26
Term (years)	2.04			2.53
Volatility	142		%	146		%
Risk-free rate	0.17		%	0.17		%
Dividend Yield	—			—

Summary of Interest Expense

The following table sets forth interest expense for our various debt obligations included on the condensed consolidated statements of operations:

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
2020 Convertible Notes	$	659	$	—	$	1,111	$	—
Accretion of debt discount - issuance costs	1,121		164		1,741		176
Accretion of debt discount - warrants	—		—		1,029		—
All other debt and financing obligations	65		296		183		385
Total	$	1,845	$	460	$	4,064	$	561