Note 16 - Preferred Stock, Common Stock and Convertible Unit Transactions (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) shares	Dec. 31, 2013 shares
Note 16 - Preferred Stock, Common Stock and Convertible Unit Transactions (Details) [Line Items]
Preferred Stock, Liquidation Preference, Value	$ 800,000	$ 975,000
Stock Repurchased During Period, Shares | shares	179,696	128,147	144,727
Stockholders' Equity Attributable to Noncontrolling Interest	$ 135,651	$ 126,980
Partners' Capital Account, Units, Converted | shares	900,000
Redeemable Series H Preferred Stock [Member]
Note 16 - Preferred Stock, Common Stock and Convertible Unit Transactions (Details) [Line Items]
Preferred Stock, Liquidation Preference, Value	$ 5,800
Series I, J or K Preferred Stock [Member]
Note 16 - Preferred Stock, Common Stock and Convertible Unit Transactions (Details) [Line Items]
Number of Votes	1,000
Number of Proxies	1,000
Number of Votes, Depositary	1
Series I Preferred Stock [Member]
Note 16 - Preferred Stock, Common Stock and Convertible Unit Transactions (Details) [Line Items]
Preferred Stock, Liquidation Preference, Value	$ 400,000	400,000
Preferred Stock, Liquidation Preference Per Share | $ / shares	$ 25,000.00
Series J Preferred Stock [Member]
Note 16 - Preferred Stock, Common Stock and Convertible Unit Transactions (Details) [Line Items]
Preferred Stock, Liquidation Preference, Value	$ 225,000	225,000
Preferred Stock, Liquidation Preference Per Share | $ / shares	$ 25,000.00
Series K Preferred Stock [Member]
Note 16 - Preferred Stock, Common Stock and Convertible Unit Transactions (Details) [Line Items]
Preferred Stock, Liquidation Preference, Value	$ 175,000	$ 175,000
Preferred Stock, Liquidation Preference Per Share | $ / shares	$ 25,000.00
Depositary Share [Member]
Note 16 - Preferred Stock, Common Stock and Convertible Unit Transactions (Details) [Line Items]
Preferred Stock, Liquidation Preference Per Share | $ / shares	$ 25.00
Convertible Units [Member]
Note 16 - Preferred Stock, Common Stock and Convertible Unit Transactions (Details) [Line Items]
Stockholders' Equity Attributable to Noncontrolling Interest	$ 24,400