Annual report pursuant to Section 13 and 15(d)

Marketable Securities - Additional Information (Detail)

v3.20.1
Marketable Securities - Additional Information (Detail)
12 Months Ended
Dec. 31, 2018
USD ($)
Security
Marketable Securities [Abstract]  
Maturity period classified current investments less than one year
Number of securities in unrealized loss position for less than one year | Security 22
Aggregate fair value of debt securities | $ $ 19,544,246