Consolidated Statement of Shareholders' Equity (Parenthetical) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Common stock dividends, share	$ 0.42	$ 0.37	$ 0.84	$ 0.74
Series A [Member]
Preferred stock dividends declared per share	884.722	914.234	1,769.444	1,866.062
Series B [Member]
Preferred stock dividends declared per share	221.18	221.18	442.36	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 I [Member]
Preferred stock dividends declared per share	640.625	640.625	640.625	640.625
Series J [Member]
Preferred stock dividends declared per share			662.50	662.50
Series K [Member]
Preferred stock dividends declared per share	$ 343.75	$ 343.75	$ 687.50	$ 687.50