Equity Common Stock Dividends (Details) - USD ($) $ / shares in Units, $ in Millions	2 Months Ended	3 Months Ended
	Apr. 23, 2018	Mar. 31, 2018	Mar. 31, 2017
Common Stock, Dividends, Per Share, Cash Paid		$ 0.13
Common Stock, Dividends, Per Share, Declared		$ 0.13	$ 0.12
Noncontrolling Interest, Increase from Sale of Parent Equity Interest		$ (1)	$ (18)
Scenario, Forecast [Member]
Common Stock, Dividends, Per Share, Declared	$ 0.13