Fair Value Measurements - Weighted-average assumptions (Details)	Dec. 31, 2019 $ / shares	Dec. 23, 2019 $ / shares
Risk-free interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt instrument measurement input	0.0179	0.0182
Expected term
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt instrument measurement input	0.0698	0.0700
Expected volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt instrument measurement input	0.80	0.80
Exercise price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt instrument measurement input	1.5200	1.5200