Convertible Notes (Interest Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Nov. 17, 2017
Interest expense related to notes
Amortization of discount and debt issuance costs	$ 207	$ 7,656	$ 7,243
Convertible senior notes
Interest expense related to notes
Total interest expense on convertible notes	$ 804	$ 10,028	$ 9,615
Convertible senior notes \| 1.375% Convertible senior notes due 2023
Interest expense related to notes
Convertible notes, stated interest rate (as a percentage)	1.375%	1.375%	1.375%	1.375%
Coupon interest expense	$ 610	$ 2,372	$ 2,372
Amortization of discount and debt issuance costs	$ 194	$ 7,656	$ 7,243

Amount of amortization expense attributable to debt discount (premium) and debt issuance costs.

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Contractual interest rate for funds borrowed, under the debt agreement.

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