Investments and Fair Value Instruments - Summary of Amortized Cost and Fair Value of Investment Securities Portfolio (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 39,439	$ 23,051
Unrealized Gains		656
Estimated Fair Value	39,439	23,707
Cash Equivalents [Member] | Money Market Funds [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	39,439	12,082
Estimated Fair Value	$ 39,439	12,082
Short-term Investments [Member] | Corporate Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost		10,969
Unrealized Gains		656
Estimated Fair Value		$ 11,625