Discontinued Operations - Reconciliation of Major Classes of Liabilities Associated with Discontinued Operations (Detail) - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total liabilities of the Terminal classified as associated with discontinued operations on the consolidated balance sheets	$ 668,000	$ 490,000
Petroleum Segment [Member] | Discontinued Operations, Held-for-sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Environmental remediation	470,000	$ 490,000
Income tax payable	$ 198,000