Fair value measurement - Valuation Technique (Details)	Dec. 31, 2020
Milestone-based payment | Discounted cash flow | Discount rate | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Business combination, contingent consideration, liability, measurement input	0.013
Milestone-based payment | Discounted cash flow | Discount rate | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Business combination, contingent consideration, liability, measurement input	0.023
Milestone-based payment | Discounted cash flow | Discount rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Business combination, contingent consideration, liability, measurement input	0.015
Revenue-based | Discounted cash flow | Discount rate | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Business combination, contingent consideration, liability, measurement input	0.065
Revenue-based | Discounted cash flow | Discount rate | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Business combination, contingent consideration, liability, measurement input	0.100
Revenue-based | Discounted cash flow | Discount rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Business combination, contingent consideration, liability, measurement input	0.091
Revenue-based | Monte Carlo simulation | Revenue volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Business combination, contingent consideration, liability, measurement input	0.224