Description of Business and Summary of Significant Accounting Policies - Summary of Fair Value Maturities for Financial Asset (Detail) $ in Thousands	Dec. 31, 2018 USD ($)
Fair Value Disclosures [Abstract]
Cash equivalents and marketable securities, Maturities by Period, Total	$ 41,921
Cash equivalents and marketable securities, Maturities by Period, Less than 1 year	41,921
Cash equivalents and marketable securities, Maturities by Period, 1-5 years	0
Cash equivalents and marketable securities, Maturities by Period, 5-10 years	0
Cash equivalents and marketable securities, Maturities by Period, More than 10 years	$ 0