Leases - Summary of Lease Portfolio (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Right-of-use assets ("ROU assets")
Operating leases	$ 5,161	$ 5,798
Operating lease, right-of-use asset, statement of financial position [Extensible List]	us-gaap:OtherAssetsNoncurrent	us-gaap:OtherAssetsNoncurrent
Finance leases	$ 21,399	$ 20,207
Finance lease, right-of-use asset, statement of financial position [Extensible List]	us-gaap:PropertyPlantAndEquipmentNet	us-gaap:PropertyPlantAndEquipmentNet
Total ROU assets	$ 26,560	$ 26,005
Current
Operating leases	$ 1,934	$ 1,875
Operating lease, liability, current, statement of financial position [Extensible List]	us-gaap:OtherLiabilitiesCurrent	us-gaap:OtherLiabilitiesCurrent
Finance leases	$ 449	$ 323
Long-term
Operating leases	$ 3,411	$ 4,084
Operating lease, liability, noncurrent, statement of financial position [Extensible List]	us-gaap:OtherLiabilitiesCurrent	us-gaap:OtherLiabilitiesNoncurrent
Finance leases	$ 22,506	$ 20,648
Total lease liabilities	$ 28,300	$ 26,930