Debt (Details) - Convertible Debt - USD ($) $ in Thousands		Jun. 30, 2021	Dec. 31, 2020
3.25% Convertible Senior Notes Due 2023 [Member]
Debt (Details) - Convertible Debt [Line Items]
Long-term Debt, Gross	[1]	$ 27,391	$ 34,134

[1] The amounts presented for the 3.25% convertible senior notes due 2023 within the table represent the fair value as of June 30, 2021 and December 31, 2020 (see Note 16 - Fair Value Measurements). The principal amount of these notes is $13.3 million and $22.9 million as of June 30, 2021 and December 31, 2020, respectively. The accrued, but unpaid, PIK interest is $0.7 million and $0.9 million as of June 30, 2021 and December 31, 2020, respectively.