Intangible Assets, Goodwill and Other Assets (Schedule of Estimated Amortization Expense) (Details) $ in Thousands	Dec. 31, 2020 USD ($)
Finite-Lived Intangible Assets [Line Items]
2021	$ 10,953
2022	10,794
2023	10,526
2024	10,211
2025	10,043
Other
Finite-Lived Intangible Assets [Line Items]
2021	2,595
2022	2,438
2023	2,171
2024	1,857
2025	1,691
Marine transportation \| Contract intangible
Finite-Lived Intangible Assets [Line Items]
2021	37
2022	35
2023	34
2024	33
2025	31
Offshore pipeline transportation \| Contract intangible
Finite-Lived Intangible Assets [Line Items]
2021	8,321
2022	8,321
2023	8,321
2024	8,321
2025	$ 8,321

Amount of amortization for assets, excluding financial assets and goodwill, lacking physical substance with finite life expected to be recognized in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

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