Note 7 - Intangible Assets, Net - Net of Accumulated Depreciation (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Customer contracts	$ 16,022	$ 16,022
Accumulated amortization of intangible assets	(10,934)	(8,491)
Total estimated aggregate amortization expense	$ 5,088	$ 7,531