Stockholders' Equity and Stock-based Compensation Expense - Activity Of Options Outstanding Under the 2019 Plans (Details)	3 Months Ended	12 Months Ended
	Mar. 31, 2024 $ / shares shares	Dec. 31, 2023 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Tax withholding ratio	1.65
Shares Available for Grant
Beginning balance (in shares)	3,554,537
Additional shares reserved (in shares)	0
Stock awards canceled / forfeited / expired (in shares)	32,396
Options canceled / forfeited / expired (in shares)	43,582
Ending balance (in shares)	2,981,015	3,554,537
Number of Stock Options Outstanding
Beginning balance (in shares)	1,282,240
Options granted in period (in shares)	520,000
Options exercised (in shares)	0
Options canceled / forfeited / expired (in shares)	(43,582)
Ending balance (in shares)	1,758,658	1,282,240
Weighted Average Exercise Price
Beginning balance (in dollars per share) | $ / shares	$ 17.97
Granted (in dollars per share) | $ / shares	2.11
Options exercised (in dollars per share) | $ / shares	0
Options canceled / forfeited / expired (in dollars per share) | $ / shares	33.88
Ending balance (in dollars per share) | $ / shares	$ 12.89	$ 17.97
Weighted Average Remaining Term (in Years)
Weighted average remaining term (in years)	7 years 10 months 13 days	8 years 2 months 15 days
RSUs
Shares Available for Grant
Options and stock awards granted (in shares)	(649,500)