Fair Value Measurements - Fair value measurement inputs (Details)	Jun. 30, 2021 $ / shares	Mar. 31, 2021 $ / shares
Stock price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Promissory note, fair value measurement inputs	4.69	3.75
Time
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Promissory note, expected term	1 year 3 months	1 year 6 months
Risk-free rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Promissory note, fair value measurement inputs	0.0012	0.0012
Volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Promissory note, fair value measurement inputs	0.437	0.506