Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Stockholders’ Equity-
Common stock, par value (in dollars per share)	$ 0.1	$ 0.1
Common stock, shares authorized	700,000,000	700,000,000
Common stock, shares outstanding	511,915,450	445,334,111
Preferred stock, par value, in dollars per share	$ 100
Preferred stock, shares authorized	5,000,000
Preferred shares shares outstanding	0	0
Customer
Receivables-
Allowance for uncollectible accounts (in dollars)	$ 50	$ 49
Other
Receivables-
Allowance for uncollectible accounts (in dollars)	$ 2	$ 1
Series A Convertible Preferred Stock
Stockholders’ Equity-
Common stock, shares outstanding	700,000	0
Preferred stock, shares authorized	1,616,000
Preferred shares shares outstanding	704,589
Affiliated companies
Receivables-
Allowance for uncollectible accounts (in dollars)	$ 920