Leases - Schedule of Lease Expense, Cash Flow, Operating and Finance Lease Assets and Liabilities, Average Lease Term and Average Discount Rate (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Finance lease expense:
Amortization of right-of-use assets	$ 615	$ 548	$ 906	$ 1,551
Interest on lease liabilities	43	34	63	65
Operating lease expense	1,699	846	2,534	2,560
Total lease expense	2,357	1,428	3,503	4,176
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash outflows from finance leases	43	34	63	65
Operating cash outflows from operating leases	1,818	821	2,692	2,484
Financing cash outflows from finance leases	467	381	723	1,035
Right-of-use assets obtained in exchange for finance lease liabilities, net of terminations and disposals	180	1,292	252	1,803
Right-of-use assets obtained in exchange for operating lease liabilities, net of terminations and disposals	422	$ 12	637	$ 18,353
Operating leases:
Other non-current assets	14,087		14,087		$ 15,201
Accrued liabilities	(2,926)		(2,926)		(2,949)
Other non-current liabilities	(12,120)		(12,120)		(13,282)
Total operating lease liabilities	(15,046)		(15,046)		(16,231)
Property and equipment gross	5,299		5,299		4,821
Accumulated depreciation	(3,024)		(3,024)		(2,118)
Property and equipment, net	2,275		2,275		2,703
Current portion of long-term debt	(893)		(893)		(1,023)
Long-term debt	(1,793)		(1,793)		(2,045)
Total finance lease liabilities	$ (2,686)		$ (2,686)		$ (3,068)
Weighted-average remaining lease term - finance leases (years)	3 years 10 months 24 days		3 years 10 months 24 days		4 years 1 month 6 days
Weighted-average remaining lease term - operating leases (years)	6 years 1 month 6 days		6 years 1 month 6 days		6 years 4 months 24 days
Weighted-average discount rate - finance leases	3.00%		3.00%		2.90%
Weighted-average discount rate - operating leases	3.80%		3.80%		3.90%