Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Allowance for credit losses:
Accounts Receivable, Allowance for Credit Loss, Current	$ (54)	$ (44)
Convertible Preferred Stock:
Series A convertible preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Series A convertible preferred stock, authorized (in shares)	3,000,000.0	3,000,000.0
Series A preferred shares, redemption amount	$ 405	$ 399
Series A preferred shares, liquidation preference	$ 405	$ 399
Series A convertible preferred stock, issued (in shares)	400,000	400,000
Series A convertible preferred stock, outstanding (in shares)	400,000	400,000
Stockholders' Equity:
Preferred Stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred Stock shares authorized (in shares)	100,000,000	100,000,000
Preferred Stock shares issued (in shares)	0	0
Preferred Stock shares outstanding (in shares)	0	0
Common Stock par value (in dollars per share)	$ 0.01	$ 0.01
Common Stock shares authorized (in shares)	500,000,000	500,000,000
Common Stock shares issued (in shares)	128,200,000	127,700,000
Common Stock shares outstanding (in shares)	128,200,000	127,700,000