Statement of Changes in Consolidated Equity (unaudited) (Parenthetical) - $ / shares	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Common stock, dividends per share (in usd per share)	$ 0.18	$ 0.12
Preferred Class A
Preferred, dividends per share (in usd per share)	1.875	1.875
Preferred Class B
Preferred, dividends per share (in usd per share)	$ 0	$ 13.4375