Condensed Consolidated Statements of Changes in Equity (Unaudited) (Parentheticals) - $ / shares	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Series I Preferred Stock [Member]
Dividends Per Depositary Share (in dollars per share)	$ 1.125	$ 1.125
Series J Preferred Stock [Member]
Dividends Per Depositary Share (in dollars per share)	1.0313	1.0313
Series K Preferred Stock [Member]
Dividends Per Depositary Share (in dollars per share)	1.0547	1.0547
Series I Preferred Stock Redeemed [Member]
Dividends Per Depositary Share (in dollars per share)	0.9625
Series L Preferred Stock [Member]
Dividends Per Depositary Share (in dollars per share)	0.1602
Dividends Per Common Share (in dollars per share)	$ 0.81	$ 0.765