Annual report pursuant to Section 13 and 15(d)

Marketable Securities - Summary of Investments in Marketable Securities (Detail)

v3.20.1
Marketable Securities - Summary of Investments in Marketable Securities (Detail) - USD ($)
Dec. 31, 2019
Dec. 31, 2018
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost   $ 29,144,000
Unrealized Gains   0
Unrealized Losses   (17,000)
Estimated Fair Value $ 0 29,127,000
Corporate debt securities 1 or less years of maturity [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost   29,144,000
Unrealized Gains   0
Unrealized Losses   (17,000)
Estimated Fair Value   $ 29,127,000