Stockholders' Deficit - Schedule of Changes in Stockholders' Deficit (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance as of September 30, 2017	$ (117)
Net loss	(10)	$ 72
Repurchase of common stock	(39)
Stock-based compensation plans	2
Dividends paid per common share	(15)
Purchase of remaining ownership interest in joint venture	(14)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Unrealized translation gain	1	(9)
Amortization of pension and other postretirement prior service credits in income	(2)	$ (2)
Balance as of December 31, 2017	$ (194)
Dividend per share (usd per share)	$ 0.0745
Repurchase of common stock (shares)	2,000,000