Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements - Additional Information (Detail)

v3.20.1
Fair Value Measurements - Additional Information (Detail) - USD ($)
Dec. 31, 2019
Dec. 31, 2018
Fair Value Disclosures [Abstract]    
Transfers from Level 1 to Level 2 $ 0 $ 0
Transfers from Level 2 to Level 1 $ 0 $ 0