Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Additional Information (Detail)

v3.19.1
Fair Value Measurements - Additional Information (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($)
Mar. 31, 2019
Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value $ 0 $ 0
Liabilities measured at fair value $ 0 $ 0