Note 10 - Investments in Affiliates (Details Textual) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Assets, Total	$ 2,494,927	$ 2,379,996
Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member]
Assets, Total	$ 113,203	$ 100,372
Asphalt Terminal Entity [Member]
Equity Method Investment, Ownership Percentage	50.00%
Assets, Total	$ 32,000
Real Estate Entities [Member]
Number of Entities	2
Real Estate Entities [Member] \| Minimum [Member]
Equity Method Investment, Ownership Percentage	10.00%
Real Estate Entities [Member] \| Maximum [Member]
Equity Method Investment, Ownership Percentage	25.00%
Real Estate Entities One [Member]
Assets, Total	$ 30,000
Real Estate Entities Two [Member]
Assets, Total	$ 51,200

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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