Consolidated Statements of Comprehensive (Loss) Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Statement Of Income And Comprehensive Income [Abstract]
Foreign currency translation adjustment, tax provision (benefit)	$ (3)	$ (10)	$ (12)
Unrealized holding gains (losses) arising during the period, tax provision			1
Pension and other postretirement benefit liability adjustments arising during the period, tax provision (benefit)	5	(1)	13
Net income attributable to noncontrolling interests, tax provision	$ 5	$ 5	$ 5