Fair Value Measurements - Assets Measured at Fair Value on a Recurring Basis (Details) - Recurring Basis - USD ($)
$ in Thousands
Dec. 31, 2021
Dec. 31, 2020
Assets:    
Assets $ 67,603 $ 81,601
Money Market Funds    
Assets:    
Cash equivalents 67,603 81,601
Not Subject to Netting    
Assets:    
Assets 67,603 81,601
Not Subject to Netting | Money Market Funds    
Assets:    
Cash equivalents $ 67,603 $ 81,601