Consolidated Statements of Equity (Parentheticals) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Common Stock [Member]
Dividends declared to common stockholders, per share (in dollars per share)	$ 1.98	$ 1.48	$ 1.75
Dividends declared to common stockholders, per share (in dollars per share)	$ 1.98	$ 1.89	$ 1.75