Stock-Based Compensation - Summary of Share Available for Grant Under the 2019 Plan (Details) - Equity Incentive Plan 2019 [Member] shares in Thousands	9 Months Ended
	Sep. 30, 2020 $ / shares shares
Shares Available for Grant
Balance at the beginning of the year (in shares)	88
Balance at the end of the period (in shares)	85
Number of Shares
Balance at the beginning of the year (in shares)	161
Options cancelled	(1)
Balance at the end of the period (in shares)	160
Weighted Average Exercise Prices
Weighted-average exercise price (in dollars per share) | $ / shares	$ 10.85
Options cancelled | $ / shares	4.00
Weighted-average exercise price (in dollars per share) | $ / shares	$ 10.90
RSU
Shares Available for Grant
Granted	(3)