Fair Value of Financial Instruments - Fair Value on a Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Assets
Cash equivalents	$ 70,689	$ 70,826
Total	70,689	70,826
Quoted Prices in Active  Markets for Identical Assets (Level 1)
Assets
Cash equivalents		70,826
Total	70,689	70,826
Significant Other Observable  Inputs (Level 2)
Assets
Cash equivalents	0	0
Total	0	0
Significant Unobservable  Inputs (Level 3)
Assets
Cash equivalents	0	0
Total	$ 0	$ 0