Discontinued Operations - Additional Information (Detail)			1 Months Ended	3 Months Ended	12 Months Ended
	Feb. 10, 2017 USD ($)	Jan. 31, 2017 Subsidiary	Nov. 30, 2019 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Environmental Incident 1994 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Costs incurred related to environmental remediation				$ 53,000	$ 553,000	$ 293,000
Accrual for environmental loss contingencies, period increase						846,000
Environmental remediation				$ 437,000	$ 490,000	$ 1,043,000
Sale of Petroleum Segment [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Reduced sales price	$ 1,040,000		$ 1,040,000
Sharing arrangement percentage	20.00%
Actual cost of the project			$ 427,000
Percentage of obligation on cost in excess of actual cost			50.00%
Entities obligation on cost in excess of actual cost			$ 1,894,008
Maximum additional obligation			$ 104,000
Terminal [Member] | Sale of Petroleum Segment [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of wholly owned subsidiaries | Subsidiary		2
Terminal [Member] | Sale of Petroleum Segment [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Reduced sales price	$ 1,040,000