Statement of Changes in Consolidated Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Common stock, dividends declared per share (usd per share)	$ 0.24	$ 0.24	$ 0.36
Preferred Class A
Preferred, dividends per share (usd per share)	3.75	3.75	3.75
Preferred Class B
Preferred, dividends per share (usd per share)	$ 0	$ 20.1563	$ 26.875