CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Jan. 10, 2018	Jun. 30, 2020	Dec. 31, 2019	Jan. 11, 2018
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 0.01	$ 0	$ 0	$ 0.001
Common stock, shares authorized (in shares)		199,000,000	199,000,000
Common stock, shares issued (in shares)		112,000,000	111,000,000
Common stock, shares outstanding (in shares)		95,000,000	94,000,000
Treasury stock, at cost, shares held (in shares)		17,000,000	17,000,000
Shares of surviving corporation (in shares)	1
Accounts Receivable, Allowance for Credit Loss, Current		$ 74	$ 36
Accounts Receivable, Allowance for Credit Loss, Noncurrent		$ 8	$ 0