Leases - Summary of Other Information Related to Operating Leases (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2019 USD ($)
Leases [Abstract]
Cash paid for amounts included in the measurement of operating lease liabilities	$ 11,016
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 21,452
Weighted-average remaining lease term – operating leases	59 months
Weighted-average discount rate – operating leases	4.60%