Note 16 - Preferred Stock, Common Stock and Convertible Unit Transactions (Details) - Outstanding Preferred Stock - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Note 16 - Preferred Stock, Common Stock and Convertible Unit Transactions (Details) - Outstanding Preferred Stock [Line Items]
Shares Authorized	6,029,100	5,959,100
Liquidation Preference (in Dollars)	$ 800,000	$ 975,000
Par Value (in Dollars per share)	$ 1.00	$ 1.00
Series I Preferred Stock [Member]
Note 16 - Preferred Stock, Common Stock and Convertible Unit Transactions (Details) - Outstanding Preferred Stock [Line Items]
Shares Authorized	18,400	18,400
Shares Issued and Outstanding	16,000	16,000
Liquidation Preference (in Dollars)	$ 400,000	$ 400,000
Dividend Rate	6.00%	6.00%
Dividend Payout (in Dollars per share)	$ 1.50000	$ 1.50000
Par Value (in Dollars per share)	$ 1.00	$ 1.00
Series J Preferred Stock [Member]
Note 16 - Preferred Stock, Common Stock and Convertible Unit Transactions (Details) - Outstanding Preferred Stock [Line Items]
Shares Authorized	9,000	9,000
Shares Issued and Outstanding	9,000	9,000
Liquidation Preference (in Dollars)	$ 225,000	$ 225,000
Dividend Rate	5.50%	5.50%
Dividend Payout (in Dollars per share)	$ 1.37500	$ 1.37500
Par Value (in Dollars per share)	$ 1.00	$ 1.00
Series K Preferred Stock [Member]
Note 16 - Preferred Stock, Common Stock and Convertible Unit Transactions (Details) - Outstanding Preferred Stock [Line Items]
Shares Authorized	8,050	8,050
Shares Issued and Outstanding	7,000	7,000
Liquidation Preference (in Dollars)	$ 175,000	$ 175,000
Dividend Rate	5.625%	5.625%
Dividend Payout (in Dollars per share)	$ 1.40625	$ 1.40625
Par Value (in Dollars per share)	$ 1.00	$ 1.00
Total [Member]
Note 16 - Preferred Stock, Common Stock and Convertible Unit Transactions (Details) - Outstanding Preferred Stock [Line Items]
Shares Authorized	35,450	105,450
Shares Issued and Outstanding	32,000	102,000
Liquidation Preference (in Dollars)	$ 800,000	$ 975,000
Series H Preferred Stock [Member]
Note 16 - Preferred Stock, Common Stock and Convertible Unit Transactions (Details) - Outstanding Preferred Stock [Line Items]
Shares Authorized		70,000
Shares Issued and Outstanding		70,000
Liquidation Preference (in Dollars)		$ 175,000
Dividend Rate		6.90%
Dividend Payout (in Dollars per share)		$ 1.72500
Par Value (in Dollars per share)		$ 1.00