Convertible Notes (Schedule of Notes) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Nov. 17, 2017
Debt instrument
Less current portion	$ 163,687	$ 0
Total long-term convertible notes	0	156,031
1.375% convertible notes due 2023 \| Convertible senior notes
Debt instrument
Face value	172,500	172,500	$ 172,500
Unamortized discount	(8,266)	(15,420)
Unamortized debt issuance costs	(547)	(1,049)
Total convertible notes	163,687	156,031
Less current portion	163,687	0
Total long-term convertible notes	$ 0	$ 156,031

Carrying value as of the balance sheet date of long-term debt (with maturities initially due after one year or beyond the operating cycle if longer) identified as Convertible Notes Payable, excluding current portion. Convertible Notes Payable is a written promise to pay a note which can be exchanged for a specified amount of another, related security, at the option of the issuer and the holder.

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Including the current and noncurrent portions, carrying value as of the balance sheet date of a written promise to pay a note, initially due after one year or beyond the operating cycle if longer, which can be exchanged for a specified amount of one or more securities (typically common stock), at the option of the issuer or the holder.

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The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

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