Equity Equity (Common Stock Dividends) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Dividends Payable [Line Items]
Dividends, Common Stock, Cash	$ 404	$ 405
Common Stock [Member]
Dividends Payable [Line Items]
Dividends Payable, Date Declared	Jan. 07, 2020	Jan. 07, 2019
Dividends Payable, Date of Record	Feb. 04, 2020	Feb. 05, 2019
Dividends Payable, Date to be Paid	Mar. 13, 2020	Mar. 13, 2019
Common Stock, Dividends, Per Share, Cash Paid	$ 0.440	$ 0.420
Dividends, Common Stock, Cash	$ 404	$ 405