CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Common stock dividends declared (USD per share)	$ 4.18	$ 3.87
Preferred Class A
Preferred stock, dividends declared per share (USD per share)	6.00	6.00
Preferred Class B
Preferred stock, dividends declared per share (USD per share)	6.75	$ 6.75
Series C Preferred Stock
Preferred stock, dividends declared per share (USD per share)	$ 27.90