Carrying amount of long-term convertible debt as of the balance sheet date, net of the amount due in the next twelve months or greater than the normal operating cycle, if longer. The debt is convertible into another form of financial instrument, typically the entity's common stock.

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Convertible Notes, Debts and Finance Leases - Convertible Roll Forwards Notes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Sep. 25, 2020	Jun. 26, 2020
Debt Instrument [Line Items]
Notes Carrying amount	$ 129,507	$ 88,629
Convertible Note due 2022 [Member]
Debt Instrument [Line Items]
Principal amount	37,707			$ 37,700
Less: Debt discount, net of amortization	(1,357)			$ (1,700)
Less: Debt issuance costs, net of amortization	(425)
Notes Carrying amount	$ 35,925
Remaining amortization period (years)	1 year 10 months 24 days
Effective interest rate on liability component	6.95%
Convertible Note due 2024 [Member]
Debt Instrument [Line Items]
Principal amount	$ 115,500	115,500	$ 115,500
Less: Debt discount, net of amortization	(19,294)	(23,652)
Less: Debt issuance costs, net of amortization	(2,624)	(3,219)
Notes Carrying amount	$ 93,582	$ 88,629
Remaining amortization period (years)	3 years 8 months 12 days	4 years 8 months 12 days
Effective interest rate on liability component	7.95%	7.95%