Leases - Summary of Cash Flow Information Related to Leases (Detail) - USD ($) $ in Thousands	1 Months Ended	9 Months Ended
	Jun. 30, 2019	Sep. 30, 2019
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases		$ 2,093
Supplemental non-cash information:
Right-of-use asset obtained in exchange for lease obligation due to remeasurement	$ 11,100	11,103
Right-of-use asset obtained in exchange for a new operating lease liability		$ 270