Income Tax (Tables)

6 Months Ended

Mar. 31, 2016

Income Tax Disclosure [Abstract]

Effective Tax Rate

Effective Tax Rate

	Three Months Ended						Six Months Ended
	March 31,						March 31,
	2016			2015			2016			2015
	(Dollars in millions)						(Dollars in millions)
Provision for income taxes	$	11		$	14		$	6		$	17
Effective tax rate		20	%		36	%		12	%		18	%