Leases - Schedule of Components of Occupancy Expense (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Lease Cost [Line Items]
Net lease cost	$ 2,611	$ 8,167
Other, net [Member]
Lease Cost [Line Items]
Operating lease cost for subleased/assigned properties	707	1,863
Sublease income subleased/assigned properties	(707)	(1,863)
Occupancy [Member]
Lease Cost [Line Items]
Operating lease cost	2,602	8,003
Variable lease costs	$ 9	$ 164