CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Parenthetical) (Unaudited) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Mar. 31, 2016	Mar. 31, 2016	Mar. 31, 2015
Statement Of Income And Comprehensive Income [Abstract]
Foreign currency translation adjustment, tax benefit			$ 1
Pension and other postretirement benefit liability adjustments arising during the period, tax provision			$ 6
Amortization of net loss and prior service credit included in net periodic pension cost, tax provision	$ 1	$ 1