Leases - Schedule of Lease Expense, Cash Flow, Operating and Finance Lease Assets and Liabilities, Average Lease Term and Average Discount Rate (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Finance lease expense:
Amortization of right-of-use assets	$ 516
Interest on lease liabilities	14
Operating lease expense:	853
Total lease expense	1,383
Cash paid for amounts included in the measurement of lease liabilities
Operating cash outflows from finance leases	14
Operating cash outflows from operating leases	828
Financing cash outflows from finance leases	325
Right-of-use assets obtained in exchange for new finance lease liabilities	556
Right-of-use assets obtained in exchange for operating lease liabilities (including adoption impact of $18.2 million)	18,285
Operating leases
Other non-current assets	17,351
Accrued liabilities	2,713
Other non-current liabilities	15,019
Total operating lease liabilities	17,732
Property and equipment gross	4,743
Accumulated depreciation	(1,438)
Property and equipment, net	3,305
Current portion of long-term debt	938
Long-term debt	1,239
Total finance lease liabilities	$ 2,177
Weighted-average remaining lease term - finance leases (years)	2 years 6 months
Weighted-average remaining lease term - operating leases (years)	7 years 1 month 6 days
Weighted-average discount rate - finance leases	2.50%
Weighted-average discount rate - operating leases	3.60%