Leases - Schedule of Components of Lease Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Finance lease cost:
Total	$ 6,873	$ 4,351	$ 16,171	$ 8,814
occupancy/equipment expense
Lessee, Lease, Description [Line Items]
Operating lease cost	6,646	4,291	15,827	8,693
occupancy expense
Finance lease cost:
Amortization of right-of-use assets	256	160	423	318
Short-term lease cost	1	1	1	2
Sub-lease income	(121)	(181)	(249)	(360)
interest expense
Finance lease cost:
Interest on lease liabilities	$ 91	$ 80	$ 169	$ 161