Convertible Notes - Schedule of Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Debt Disclosure [Abstract]
Interest expense	$ 1,072	$ 1,072	$ 3,216	$ 3,216
Amortization of the debt discount	2,666	2,379	7,775	6,940
Amortization of debt issuance costs	165	147	481	429
Interest Expense, Debt	$ 3,903	$ 3,598	$ 11,472	$ 10,585