Income Tax (Tables)

9 Months Ended

Jun. 30, 2017

Income Tax Disclosure [Abstract]

Effective Tax Rate

Effective Tax Rate

	Three Months Ended						Nine Months Ended
	June 30,						June 30,
	2017			2016			2017			2016
	(Dollars in millions)
Provision (benefit) for income taxes	$	16		$	15		$	32		$	21
Effective tax rate		22	%		21	%		14	%		17	%