Note 2 - Other Assets (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Capitalized Computer Software, Accumulated Amortization	$ 19,100		$ 19,100
Goodwill and Intangible Asset Impairment	0	$ 0	0	$ 0
Other Assets [Member]
Indefinite-Lived Franchise Rights		7,000		7,000	$ 7,000
Computer Software, Intangible Asset [Member]
Interest Costs Capitalized			$ 30,500
Finite-Lived Intangible Asset, Useful Life			15 years
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months		3,400		3,400
Finite-Lived Intangible Assets, Amortization Expense, Year Two	3,400		$ 3,400
Finite-Lived Intangible Assets, Amortization Expense, Year Three	3,400		3,400
Finite-Lived Intangible Assets, Amortization Expense, Year Four	3,400		3,400
Finite-Lived Intangible Assets, Amortization Expense, Year Five	3,400		3,400
Computer Software, Intangible Asset [Member] | Depreciation and Amortization [Member]
Amortization of Intangible Assets	$ 900	$ 900	$ 2,600	$ 2,500