Statement of Changes in Consolidated Equity (unaudited) (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Common stock, dividends per share (in usd per share)	$ 0.06	$ 0.12	$ 0.24	$ 0.24
Preferred Class A
Preferred, dividends per share (in usd per share)	$ 0.9375	1.875	$ 2.8125	3.75
Preferred Class B
Preferred, dividends per share (in usd per share)		$ 6.71875		$ 20.1563