Leases - Schedule of Maturity Analysis of Lease Liability by Lease Classification (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Operating Leases
Operating Leases, 2019	$ 8,668
Operating Leases, 2020	16,764
Operating Leases, 2021	15,690
Operating Leases, 2022	14,131
Operating Leases, 2023	9,674
Operating Leases, Thereafter	69,003
Operating Leases, Total undiscounted lease payments	133,930
Amounts representing interest, Operating Leases	(23,334)
Operating Leases, Lease liability	110,596	$ 0	$ 0
Finance Leases
Finance Leases, 2019	400
Finance Leases, 2020	803
Finance Leases, 2021	809
Finance Leases, 2022	815
Finance Leases, 2023	830
Finance Leases, Thereafter	6,231
Finance Leases, Total undiscounted lease payments	9,888
Amounts representing interest, Finance Leases	(2,242)
Finance Leases, Lease liability	$ 7,646