Available-for-Sale Marketable Securities - Additional Information (Detail) $ in Thousands	Jun. 30, 2020 USD ($) position	Dec. 31, 2019 USD ($) position
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale allowance for credit loss | $	$ 0	$ 0
Number of available-for-sale marketable securities in unrealized loss positions	2	16
Total number of positions	42	81
Available-for-sale marketable securities, continuous unrealized loss position, 12 Months or Greater, Gross Unrealized Losses | $	$ 0	$ 0
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of available-for-sale marketable securities in unrealized loss positions	2
Total number of positions	28