Fair Value Measurements - Additional Information (Detail) - Discount for Lack of Marketability	Mar. 31, 2020
Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Valuation analysis of equity securities	18.50%
Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Valuation analysis of equity securities	30.00%
Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Valuation analysis of equity securities	26.20%