Condensed Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 280	$ 145
Unrealized foreign currency translation and other adjustments	15	(21)
Pension and other retirement benefits adjustments (net of taxes for the three months ended December 31, 2017 and 2016 of $8 and $9, respectively)	14	16
Foreign currency cash flow hedge adjustments (net of taxes for the three months ended December 31, 2017 and 2016 of $(1) and $0, respectively)	(2)	(3)
Comprehensive income	$ 307	$ 137