Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2020

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

The following tables summarize the Company's financial liabilities measured at fair value on a recurring basis as of September 30, 2020 and December 31, 2019 (in thousands):

	Carrying Amount as of September 30, 2020		Fair Value Measurements as of September 30, 2020
			Level 1		Level 2		Level 3
3.25% convertible senior notes due in 2023	$	38,401	$	—	$	—	$	38,401
Preferred stock derivative liability		5,871		—		—		5,871

	Carrying Amount as of December 31, 2019		Fair Value Measurements as of December 31, 2019
			Level 1		Level 2		Level 3
3.25% convertible senior notes due in 2023	$	50,753	$	—	$	—	$	50,753
Preferred stock derivative liability		5,247		—		—		5,247

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]

The following tables provide a reconciliation of the beginning and ending balances of liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) (in thousands):

3.25% convertible senior notes due in 2023	2020			2019
Balance, January 1,	$	50,753		$	—
New issuance ($29.6 million face value)		—			37,916
New issuance ($8.0 million face value)		—			10,254
Conversion of convertible senior notes		(10,733	)		—
Change in fair value		(2,757	)		465
Payment-in-kind interest		1,138			—
Balance, September 30,	$	38,401		$	48,635

Preferred stock derivative liability	2020		2019
Balance, January 1,	$	5,247	$	—
New issuance of Series A Preferred Stock		—		4,894
Change in fair value		624		—
Balance, September 30,	$	5,871	$	4,894