Leases - Schedule of Lease Cost and Other Information (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Lease Cost
Operating lease cost	$ 2,698	$ 8,097
Short-term lease cost	1,249	3,367
Variable lease cost	303	884
Total lease cost	4,250	12,348
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flow from operating leases	2,718	8,139
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 1,593	$ 2,482