Convertible Notes - Schedule of Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Debt Disclosure [Abstract]
Contractual coupon interest	$ 1,024	$ 1,072	$ 3,168	$ 3,216
Amortization of the debt discount	2,987	2,666	8,711	7,775
Amortization of debt issuance costs	185	165	539	481
Total interest expense on convertible notes	$ 4,196	$ 3,903	$ 12,418	$ 11,472