Fair Value Measurements (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Common stock warrant liability	$ 1	$ 601
Fair value on a recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Common stock warrant liability	1	601
Fair value on a recurring basis | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Common stock warrant liability	0
Fair value on a recurring basis | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Common stock warrant liability	$ 1	$ 601