Leases - Summary of Lease Portfolio (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Right-of-use assets ("ROU assets")
Operating leases	$ 3,571	$ 4,840
Operating lease, right-of-use asset, statement of financial position [Extensible List]	Other long-term assets	Other long-term assets
Finance leases	$ 19,114	$ 20,552
Finance lease, right-of-use asset, statement of financial position [Extensible List]	Property, plant, and equipment, net	Property, plant, and equipment, net
Total ROU assets	$ 22,685	$ 25,392
Current
Operating leases	$ 2,002	$ 2,092
Operating lease, liability, current, statement of financial position [Extensible List]	Other current liabilities	Other current liabilities
Finance leases	$ 2,570	$ 510
Long-term
Operating leases	$ 1,713	$ 2,946
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other long-term liabilities	Other long-term liabilities
Finance leases	$ 20,044	$ 22,338
Total lease liabilities	$ 26,329	$ 27,886