Leases - Schedule of Lease Cost and Other Information (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Lease Cost
Operating lease cost	$ 2,711	$ 5,399
Short-term lease cost	1,148	2,118
Variable lease cost	233	581
Total lease cost	4,092	8,098
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flow from operating leases	2,725	5,421
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 595	$ 889