Convertible Notes (Tables)

12 Months Ended

Dec. 31, 2019

Debt Instrument [Line Items]

Carrying value and unamortized discount on December [Table Text Block]

The carrying value, accretion and unamortized discount of the December 2024 Notes were as follows:

(in thousands)	December 31, 2019
Principal amount of the December 2024 Notes	$	11,500
Unamortized discount of liability component	(1,200		)
Net carrying value of the December 2024 Notes	$	10,300

Schedule of interest expense for December 2024 Notes [Table Text Block]

Interest expense for the December 2024 Notes included in the Company’s Consolidated Statement of Operations was as follows:

	Year Ended
(in thousands)	December 31, 2019
Contractual coupon interest	$	598
Accretion Interest on outstanding principal	517
Amortization of debt issuance costs	53
Amortization of conversion feature	350
Total	$	1,518

Schedule of carrying value and unamortized discount on December 2021 Notes [Table Text Block]

The carrying value and unamortized discount of the December 2021 Notes were as follows:

(in thousands)	December 31, 2019			December 31, 2018
Principal amount of the December 2021 Notes	$	19,170		$	150,000
Unamortized discount of liability component	(2,220		)	(25,356		)
Net carrying value of the December 2021 Notes	$	16,950		$	124,644

Schedule of convertible and non-recourse notes activity

Schedule of Maturities of Long-term Debt [Table Text Block]

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Schedule of carrying value and unamortized discount on February 2018 Notes [Table Text Block]

Schedule of interest expense for February 2018 Notes [Table Text Block]

Interest expense for the February 2018 Notes on the Company’s Consolidated Statements of Operations was as follows:

	Year Ended December 31,
(in thousands)	2019		2018		2017
Contractual coupon interest	$	—	$	422	$	5,058
Amortization of debt issuance costs	—		88		1,022
Amortization of debt discount	—		293		3,449
Total	$	—	$	803	$	9,529

Schedule of interest expense for December 2021 Notes [Table Text Block]

Interest expense for the December 2021 Notes included in the Company’s Consolidated Statements of Operations was as follows:

	Year Ended December 31,
(in thousands)	2019		2018
Contractual coupon interest	$	3,390	$	4,125
Amortization of debt issuance costs	64		76
Amortization of debt discount	459		542
Amortization of conversion feature	5,973		6,611
Total	$	9,886	$	11,354