Quarterly report pursuant to Section 13 or 15(d)

Marketable Securities - Summary of Marketable Securities (Detail)

v3.19.3
Marketable Securities - Summary of Marketable Securities (Detail) - USD ($)
$ in Thousands
Sep. 30, 2019
Dec. 31, 2018
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost $ 4,367 $ 29,144
Unrealized Gains 1 0
Unrealized Losses 0 (17)
Estimated Fair Value 4,368 29,127
Corporate debt securities 1 or less years of maturity [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 4,367 29,144
Unrealized Gains 1 0
Unrealized Losses 0 (17)
Estimated Fair Value $ 4,368 $ 29,127