Convertible Notes Schedule of interest expense for December 2021 Notes (Details) - February 2018 Notes [Member] - USD ($) $ in Thousands		12 Months Ended
Sep. 18, 2019	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Contractual coupon interest		$ 3,390	$ 4,125
Amortization of debt issuance costs		64	76
Amortization of Debt Discount (Premium)		459	542
Adjustments to Additional Paid in Capital, Convertible Debt with Conversion Feature	$ (13,500)	5,973	6,611
Total		$ 9,886	$ 11,354

Amortization of debt issuance costs

No definition available.

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- Definition

Amount of increase (decrease) in additional paid in capital (APIC) resulting from recognition of deferred taxes for convertible debt with a beneficial conversion feature.

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Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of the cost of borrowed funds accounted for as interest expense for debt.

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Represents the portion of interest incurred in the period on debt arrangements that was charged against earnings, excluding amortization of debt discount (premium) and financing costs.

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