Leases - Schedule of Future Minimum Rental Payments For Finance and Operating Leases (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Leases [Abstract]
Finance Leases, 2019	$ 880
Finance Leases, 2020	741
Finance Leases, 2021	394
Finance Leases, 2022	223
Finance Leases, 2023	12
Finance Leases, Total	2,250
Finance Leases, Less: Imputed Interest	(73)
Finance Leases, Total lease liabilities, net of interest	2,177
Operating Leases, 2019	2,388
Operating Leases, 2020	3,208
Operating Leases, 2021	2,810
Operating Leases, 2022	2,413
Operating Leases, 2023	2,167
Operating Leases, Thereafter	6,897
Operating Leases, Total	19,883
Operating Leases, Less: Imputed Interest	(2,151)
Operating Leases, Total lease liabilities, net of interest	$ 17,732
2019		$ 4,249
2020		3,232
2021		2,870
2022		2,635
2023		2,346
Thereafter		7,647
Total		$ 22,979