Consolidated Statement of Shareholders' Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Common stock dividends, share	$ 0.37	$ 0.30	$ 0.74	$ 0.60
Series A [Member]
Preferred stock dividends declared per share	914.234	884.722	1,866.062	1,759.722
Series B [Member]
Preferred stock dividends declared per share	221.18	221.18	439.93	439.93
Series F [Member]
Preferred stock dividends declared per share	406.25	406.25	812.50	812.50
Series H [Member]
Preferred stock dividends declared per share	321.88	321.88	643.76	643.76
Series J [Member]
Preferred stock dividends declared per share			662.50	662.50
Series K [Member]
Preferred stock dividends declared per share	343.75		687.50
Series I [Member]
Preferred stock dividends declared per share	$ 640.625	$ 640.625	$ 640.625	$ 640.625