Consolidated Statements of Changes in Equity (Parentheticals) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Series H Preferred Stock [Member]
Dividends Per Depositary Share (in dollars per share)		$ 1.485	$ 1.725
Series I Preferred Stock [Member]
Dividends Per Depositary Share (in dollars per share)	$ 1.50	1.50	1.50
Series J Preferred Stock [Member]
Dividends Per Depositary Share (in dollars per share)	1.375	1.375	1.375
Series K Preferred Stock [Member]
Dividends Per Depositary Share (in dollars per share)	1.40625	$ 1.40625	1.40625
Additional Paid-in Capital [Member]
Sale of interests in investments, tax		$ 16
Dividends Per Common Share (in dollars per share)	$ 1.035	$ 0.975	$ 0.915