Convertible Notes (Details 2) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Interest expense related to notes
Amortization of discount and debt issuance costs			$ 5,394	$ 5,104
Interest expense	$ 2,586	$ 2,497	7,721	7,302
Convertible senior notes \| 1.375% Convertible senior notes due 2023
Interest expense related to notes
Interest	593	593	1,779	1,779
Amortization of discount and debt issuance costs	1,823	1,725	5,394	5,104
Interest expense	$ 2,416	$ 2,318	$ 7,173	$ 6,883
Convertible notes, stated interest rate (as a percentage)	1.375%	1.375%	1.375%	1.375%
Effective interest rate of the liability component (as a percentage)	4.90%	4.90%	4.90%	4.90%

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

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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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