Leases - Schedule of Maturity Analysis of Lease Liability by Lease Classification (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018
Operating Leases
Operating Leases, 2019	$ 13,094
Operating Leases, 2020	16,764
Operating Leases, 2021	15,690
Operating Leases, 2022	14,131
Operating Leases, 2023	9,674
Operating Leases, Thereafter	68,974
Operating Leases, Total undiscounted lease payments	138,327
Less amounts representing interest, Operating Leases	(24,287)
Operating Leases, Lease liability	114,040	$ 0	$ 0
Finance Leases
Finance Leases, 2019	573
Finance Leases, 2020	768
Finance Leases, 2021	772
Finance Leases, 2022	778
Finance Leases, 2023	791
Finance Leases, Thereafter	6,030
Finance Leases, Total undiscounted lease payments	9,712
Less amounts representing interest, Finance Leases	(2,280)
Finance Leases, Lease liability	$ 7,432