Subsequent Events (Details) - USD ($)		1 Months Ended	12 Months Ended
	Feb. 26, 2021	Feb. 28, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jan. 31, 2021	Mar. 31, 2019
Subsequent Event [Line Items]
Shares of common stock reserved for issuance (in shares)			1,010,843	848,023	629,716
Weighted average grant date fair value (in USD per share)			$ 18.22	$ 10.17	$ 2.93
Exercise price (in USD per share)			$ 40.67	$ 22.77	$ 6.51
Common stock reserved for future issuance (in shares)			6,660,892	6,237,832
Contingent liabilities requiring accrual			$ 0	$ 0
Voluntary Recall
Subsequent Event [Line Items]
Loss contingency receivable			4,160,000
Contingent liabilities requiring accrual			1,696,000
Loss Contingency Receivable, Inventory Held | Voluntary Recall
Subsequent Event [Line Items]
Loss contingency receivable			2,227,000
Loss Contingency Receivable, Inventory in Process of Recall | Voluntary Recall
Subsequent Event [Line Items]
Loss contingency receivable			1,696,000
Loss Contingency Receivable, Direct Costs | Voluntary Recall
Subsequent Event [Line Items]
Loss contingency receivable			$ 237,000
2019 ESPP
Subsequent Event [Line Items]
Common stock reserved for future issuance (in shares)			746,552				434,000
Restricted stock units
Subsequent Event [Line Items]
Restricted stock vested (in shares)			0
2019 Equity Incentive Plan
Subsequent Event [Line Items]
Shares of common stock reserved for issuance (in shares)			3,635,009				2,317,000
Subsequent Event | 2019 ESPP
Subsequent Event [Line Items]
Common stock reserved for future issuance (in shares)						342,496
Subsequent Event | Restricted stock units
Subsequent Event [Line Items]
Restricted stock vested (in shares)	14,952
Trailing stock price period	30 days
Subsequent Event | 2019 Equity Incentive Plan
Subsequent Event [Line Items]
Shares of common stock reserved for issuance (in shares)						1,369,985
Shares of common stock reserved for issuance (in shares)		19,305
Exercise price (in USD per share)		$ 59.33