Leases - Summary of Lease Costs and Other Information Pertaining to Operating Leases (Detail) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)
Lease cost
Operating lease cost	$ 8,917	$ 17,400
Total lease cost	$ 8,917	17,400
Operating cash flows used for operating leases		$ 13,237
Weighted average remaining lease term	7 years 8 months 12 days	7 years 8 months 12 days
Weighted average discount rate	6.17%	6.17%