Condensed Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Cash and Cash Equivalents
Restricted Cash and Cash Equivalents, Current	$ 15	$ 15
Accounts Receivable
net allowance for doubtful accounts	$ 16	$ 16
Common Stock
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
shares authorized	300,000,000	300,000,000
Common Stock, Shares, Issued	170,605,906	170,605,906
shares outstanding	82,556,847	82,556,847
Treasury stock, shares	88,049,059	88,049,059