Note 15 - Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2020

Notes Tables

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

	Level 1		Level 2		Level 3		Total
December 31, 2020
Liabilities:
Fuel hedge	$	—	$	—	$	297	$	297
Interest rate swaps		—		—		3,893		3,893
	$	—	$	—	$	4,190	$	4,190
December 31, 2019
Assets:
Fuel hedge	$	—	$	—	$	25	$	25
Marketable securities - restricted (Note 4)		2,296		—		—		2,296
	$	2,296	$	—	$	25	$	2,321
Liabilities:
Interest rate swaps	$	—	$	—	$	3,825	$	3,825

Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]

Ending balance, December 31, 2018	$	(1,639	)
Change in estimated fair value		(2,161	)
Ending balance, December 31, 2019		(3,800	)
Change in estimated fair value		(390	)
Ending balance, December 31, 2020*	$	(4,190	)