Fair Value - Fair Value Option Notes (Details) $ / shares in Units, $ in Thousands	Dec. 31, 2020 USD ($) $ / shares	Dec. 31, 2019 USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Initial principal value	$ 50,831	$ 54,031
Value upon maturity	47,983	49,461
FVO Note 1
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Initial principal value	2,500
Value upon maturity	$ 6,682
Conversion price (per share) | $ / shares	$ 6.39
Estimated fair value of FVO Note	$ 5,079
FVO Note 1 | Current stock price | Series A redeemable convertible preferred stock
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
FVO Notes	14.12
FVO Note 1 | Expected term
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
FVO Notes	2
FVO Note 1 | Volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
FVO Notes	39
FVO Note 1 | Risk free rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
FVO Notes	1.58
FVO Note 2
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Initial principal value		3,000
Value upon maturity		6,602
Estimated fair value of FVO Note		$ 6,580