CONSOLIDATED STATEMENTS OF EQUITY (Parenthetical) - $ / shares	3 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2018
Common stock, dividend per share paid (in dollars per share)	$ 0.21	$ 0.21	$ 0.21	$ 0.21
Preferred shares, par value (in dollars per share)	0.01	0.01	0.01	0.01
Common stock, par value (in dollars per share)	1.00	1.00	1.00	1.00	$ 1.00
Series B Preferred Stock
Preferred stock, dividends per share paid (in dollars per share)	0.4609	0.4609	0.4609	0.4609
Preferred shares, par value (in dollars per share)	0.01	0.01	0.01	0.01	0.01
Series C Preferred Stock
Preferred stock, dividends per share paid (in dollars per share)	0.45	0.45	0.4500	0.4500
Preferred shares, par value (in dollars per share)	0.01	0.01	0.01	0.01	0.01
Series D Preferred Stock
Preferred stock, dividends per share paid (in dollars per share)	0.4297	0.4297	0.4297	0.4297
Preferred shares, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01