Leases - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Jan. 01, 2019
Leases [Abstract]
Operating lease right-of-use assets	$ 42,936	$ 42,936	$ 10,400
Operating lease liability	43,074	43,074	$ 10,400
Operating lease cost	4,300	12,200
Operating lease liability current	$ 12,889	$ 12,889
Weighted average remaining lease term	4 years	4 years
Weighted average discount cate	5.40%	5.40%