Annual report pursuant to Section 13 and 15(d)

Investments and Fair Value Measurements - Category of Financial Instruments Not Held at Fair Value (Detail)

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Investments and Fair Value Measurements - Category of Financial Instruments Not Held at Fair Value (Detail) - USD ($)
$ in Thousands
Dec. 31, 2019
Dec. 31, 2018
Carrying Amount    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Financial Assets, Investments $ 1,781 $ 1,493
Carrying Amount | Level I    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Financial Assets, Cash and cash equivalents 52,832 69,283
Carrying Amount | Level II    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Financial Liabilities, Borrowings under credit facility 16,200  
Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Financial Assets, Investments 1,781 1,493
Fair Value | Level I    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Financial Assets, Cash and cash equivalents 52,832 $ 69,283
Fair Value | Level II    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Financial Liabilities, Borrowings under credit facility $ 16,200