STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Revenue	$ 40,352	$ 21,347
Cost of goods sold	5,981	3,297
Gross profit	34,371	18,050
Operating expenses:
Research and development	8,154	5,438
Selling, general and administrative	41,906	29,052
Total operating expenses	50,060	34,490
Operating loss	(15,689)	(16,440)
Other expense (income):
Interest income	(57)	(642)
Interest expense	523	525
Other expense (income), net	38	(78)
Total other expense (income)	504	(195)
Loss before income taxes	(16,193)	(16,245)
Income taxes	23	0
Net loss	(16,216)	(16,245)
Other comprehensive loss:
Unrealized (loss) gain on investments	(20)	193
Total comprehensive loss	$ (16,236)	$ (16,052)
Net loss per share, basic and diluted (in dollars per share)	$ (0.60)	$ (0.67)
Weighted average common shares used to compute net loss per share, basic and diluted (in shares)	27,144,361	24,165,875