Consolidated Statements of Operations - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Net sales	$ 83,699,000	$ 68,126,000	$ 36,542,000
Cost of goods sold	33,012,000	26,822,000	14,171,000
Gross profit	50,687,000	41,304,000	22,371,000
Operating expenses:
Sales and marketing	80,189,000	67,715,000	33,911,000
Research and development	13,537,000	10,945,000	9,813,000
General and administrative	46,771,000	42,418,000	31,537,000
Restructuring	1,083,000
Legal settlement			10,000,000
Goodwill and other intangible impairment	12,674,000
Total operating expenses	154,254,000	121,078,000	85,261,000
Loss from operations	(103,567,000)	(79,774,000)	(62,890,000)
Other income (expense), net:
Interest income	1,406,000	532,000	172,000
Interest expense	(4,568,000)	(3,428,000)	(1,232,000)
Other income (expense), net	(55,000)	39,000	(95,000)
Total other income (expense), net	(3,217,000)	(2,857,000)	(1,155,000)
Loss before income taxes	(106,784,000)	(82,631,000)	(64,045,000)
Income tax (benefit) expense	34,000	(4,000)	(17,000)
Net loss	$ (106,818,000)	$ (82,627,000)	$ (64,028,000)
Basic and diluted net loss per share attributable to common stockholders	$ (2.63)	$ (3.25)	$ (3.34)
Weighted average outstanding common shares used for net loss per share attributable to common stockholders:
Basic and diluted	40,654,272	25,402,241	19,159,057