Earnings per Share - Earnings per share reconciliation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Schedule of Basic And Diluted Earnings [Line Items]
Adjusted Net Income Available to Common Shareholders, Common	$ (51)	$ (310)
Preferred Stock Dividends and Other Adjustments	2	2
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent	$ (49)	$ (308)
Weighted Average Number of Shares Outstanding, Basic	211,093	207,944
Income (Loss) from Continuing Operations, Per Basic Share	$ (0.24)	$ (1.49)
Earnings Per Share, Basic	$ (0.24)	$ (1.49)
Weighted Average Number of Shares Outstanding, Diluted	211,093	207,944
Income (Loss) from Continuing Operations, Per Diluted Share	$ (0.24)	$ (1.49)
Earnings Per Share, Diluted	$ (0.24)	$ (1.49)
Stock Options [Member]
Schedule of Basic And Diluted Earnings [Line Items]
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	0	0
Restricted Stock and Performance Shares [Member]
Schedule of Basic And Diluted Earnings [Line Items]
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	0	0