Condensed Consolidated Statements of Changes in Equity (Unaudited) (Parentheticals) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Common Stock [Member]
Dividends per common share (in dollars per share)	$ 0.51	$ 0.48
Preferred Stock [Member] | Series H Preferred Stock [Member]
Dividends per depository share (in dollars per share)		0.8625
Preferred Stock [Member] | Series I Preferred Stock [Member]
Dividends per depository share (in dollars per share)	0.75	0.75
Preferred Stock [Member] | Series J Preferred Stock [Member]
Dividends per depository share (in dollars per share)	0.6875	0.6875
Preferred Stock [Member] | Series K Preferred Stock [Member]
Dividends per depository share (in dollars per share)	$ 0.7032	$ 0.7032
Additional Paid-in Capital [Member]
Sale of interests in investments, tax		$ 16