Quarterly report pursuant to Section 13 or 15(d)

Investments and Fair Value Measurements - Additional Information (Detail)

v3.19.2
Investments and Fair Value Measurements - Additional Information (Detail) - USD ($)
Jun. 30, 2019
Dec. 31, 2018
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Investments $ 16,000 $ 1,493,000
Fair Value, Measurements, Recurring    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Financial assets 0 0
Financial liabilities $ 0 $ 0
Maximum    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Maximum financial interest in affiliated investment funds 2.00%