Note 12 - Preferred Stock, Common Stock and Convertible Unit Transactions - Preferred Stock Issued (Details) - USD ($) $ / shares in Units, $ in Thousands		9 Months Ended
	Aug. 16, 2017	Sep. 30, 2016
Net Proceeds, After Expenses		$ 285,864
Series L Preferred Stock [Member]
Depositary Shares Issued (in shares)	9,000,000
Net Proceeds, After Expenses	$ 217,600
Offering/ Redemption Price (in dollars per share)	$ 25