Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Additional Information (Detail)

v3.19.2
Fair Value Measurements - Additional Information (Detail)
6 Months Ended
Jun. 30, 2019
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]  
Maximum maturity period of cash and cash equivalents 90 days
Maximum maturity period of short-term investments 1 year
Maximum [Member]  
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]  
Maturity period of securities 1 year