Fair Value Measurement - Summary of Assumptions Used to Estimate Fair Value of Contingent Payments (Detail) - Level 3 [Member]	6 Months Ended
	Jun. 30, 2020
Expected Volatility [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assumptions used to estimate fair value of contingent payments	1.129
Expected Volatility [Member] | Weighted Average [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assumptions used to estimate fair value of contingent payments	1.129
Risk-free Interest Rate [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assumptions used to estimate fair value of contingent payments	0.0016
Risk-free Interest Rate [Member] | Weighted Average [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assumptions used to estimate fair value of contingent payments	0.0016
Cost of Capital [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assumptions used to estimate fair value of contingent payments	0.300
Cost of Capital [Member] | Weighted Average [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assumptions used to estimate fair value of contingent payments	0.300
Discount for Lack of Marketability [Member] | Minimum [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assumptions used to estimate fair value of contingent payments	0.14
Discount for Lack of Marketability [Member] | Maximum [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assumptions used to estimate fair value of contingent payments	0.22
Discount for Lack of Marketability [Member] | Weighted Average [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assumptions used to estimate fair value of contingent payments	0.180
Probability of Payment [Member] | Minimum [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assumptions used to estimate fair value of contingent payments	0.52
Probability of Payment [Member] | Maximum [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assumptions used to estimate fair value of contingent payments	0.83
Probability of Payment [Member] | Weighted Average [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assumptions used to estimate fair value of contingent payments	0.76
Projected Year of Payment [Member] | Minimum [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assumptions used to estimate fair value of contingent payments	2020
Projected Year of Payment [Member] | Maximum [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assumptions used to estimate fair value of contingent payments	2022
Projected Year of Payment [Member] | Weighted Average [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assumptions used to estimate fair value of contingent payments	2020