Fair Value Measurements - Liabilities Measure at Fair Value Preferred Stock (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liability, fair value, gross liability	$ 9,956
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Noncurrent Liabilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liability, fair value, gross liability	9,956
Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liability, fair value, gross liability	671	$ 3,117
Significant Unobservable Inputs (Level 3) | Other Current Liabilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liability, fair value, gross liability		2,453
Significant Unobservable Inputs (Level 3) | Other Noncurrent Liabilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liability, fair value, gross liability	$ 671	$ 664