Note 10 - Investments in Affiliates (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021
Assets, Total		$ 2,167,933	$ 2,402,652	$ 2,284,906	$ 2,263,279	$ 2,494,927
Real Estate Entities [Member]
Assets, Total		$ 366,800
Number of Entities		2
Real Estate Entities One [Member]
Assets, Total		$ 31,000
Real Estate Entities Two [Member]
Assets, Total		40,200
Foreign Affiliates [Member]
Assets, Total		264,600
Asphalt Terminal Entity [Member]
Assets, Total		$ 31,000
Asphalt Terminal Entity [Member]
Equity Method Investment, Ownership Percentage		50.00%
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%
Foreign Affiliates [Member]
Equity Method Investment, Other than Temporary Impairment	$ 9,600
Foreign Affiliates [Member] | Minimum [Member]
Equity Method Investment, Ownership Percentage		25.00%
Foreign Affiliates [Member] | Maximum [Member]
Equity Method Investment, Ownership Percentage		50.00%