Statements of Equity and Accumulated Deficit Parenthetical - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Common Stock, Dividends, Per Share, Declared	$ 1.0475	$ 1.02	$ 0.94
Series A Preferred Stock [Member]
Preferred Stock, Dividends Per Share, Declared	5.00	5.00	5.00
Minimum [Member] | Series M Preferred Stock [Member]
Preferred Stock, Dividends Per Share, Declared	4.79	4.79	4.79
Maximum [Member] | Series M Preferred Stock [Member]
Preferred Stock, Dividends Per Share, Declared	$ 6.25	$ 6.25	$ 6.25