Convertible Notes - Schedule of Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Debt Disclosure [Abstract]
Contractual coupon interest	$ 1,072	$ 1,072	$ 2,144	$ 2,144
Amortization of the debt discount	2,903	2,591	5,724	5,109
Amortization of debt issuance costs	180	160	354	316
Total interest expense on convertible notes	$ 4,155	$ 3,823	$ 8,222	$ 7,569