Nature of Business and Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Basis Of Presentation [Line Items]
Common stock, par value (in usd per share)	$ 0.001	$ 0.001
Preferred stock, par value (in usd per share)	$ 0.001
Cash	$ 111,584,000	$ 63,888,000
Net cash flows from operating activities	25,000,000.0
Stockholders' equity	108,234,000	69,764,000	$ 29,742,000	$ 8,877,000
Allowance for doubtful accounts receivable	10,000.00	0
Inventory reserve	2,254,000	384,000
Depreciation	500,000	1,800,000	700,000
Impairment loss	0	0	78,000
Impairment charges recognized on finite lived intangibles assets	0	0	0
Goodwill impairment charges	$ 0	0	0
Sales return maximum duration	18 months
Offered period for sales return prior to expiration	6 months
Offered period for sales return subsequent to expiration	12 months
Research and development	$ 0	0	4,903,000
Advertising expenses	11,000,000.0	10,800,000	4,500,000
Shipping and handling costs	24,665,000	21,590,000	15,783,000
Trade receivables	$ 54,700,000
Less than 30 days
Basis Of Presentation [Line Items]
Accounts receivable outstanding, percentage	98.00%
BUNAVAIL
Basis Of Presentation [Line Items]
Inventory reserve		200,000
Depreciation	$ 1,500,000	1,500,000
Impairment loss	300,000	0
Reserve liability, product returns	2,200,000
Shipping and Handling
Basis Of Presentation [Line Items]
Shipping and handling costs	$ 30,000.00	$ 30,000.00	$ 20,000.00
Minimum
Basis Of Presentation [Line Items]
Estimated useful lives of equipment	3 years
Maximum
Basis Of Presentation [Line Items]
Estimated useful lives of equipment	10 years