Revenue Recognition - Cumulative Effect and Impact of New Accounting Pronouncements (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended						9 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Jun. 30, 2019	Jun. 30, 2018	Oct. 01, 2018	Sep. 30, 2018
Statement of Financial Position [Abstract]
Accounts receivable, net	$ 423						$ 423		$ 376	$ 409
Inventories, net	200						200		190	176
Deferred income taxes	113						113		144	138
Accrued expenses and other liabilities	242						242			203
Retained deficit	291						291		412	399
Statement of Comprehensive Income [Abstract]
Sales	613			$ 577			1,761	$ 1,691
Cost of sales	406			376			1,168	1,088
Gross profit	207			201			593	603
Selling, general and administrative expenses	116			110			334	328
Equity and other income, net	11			8			29	29
Operating income	102			102			285	290
Income before income taxes	85			97			237	275
Income tax expense	20			33			56	154
Net income	$ 65	$ 63	$ 53	$ 64	$ 67	$ (10)	$ 181	$ 121
Basic earnings per share (usd per share)	$ 0.34			$ 0.33			$ 0.96	$ 0.61
Diluted earnings per share (usd per share)	$ 0.34			$ 0.33			$ 0.96	$ 0.61
Under prior guidance
Statement of Financial Position [Abstract]
Accounts receivable, net	$ 460						$ 460			409
Inventories, net	185						185			176
Deferred income taxes	107						107			138
Accrued expenses and other liabilities	241						241
Retained deficit	276						276			$ 399
Statement of Comprehensive Income [Abstract]
Sales	603						1,727
Cost of sales	392						1,126
Gross profit	211						601
Selling, general and administrative expenses	119						340
Equity and other income, net	12						30
Operating income	104						288
Income before income taxes	87						240
Income tax expense	21						57
Net income	$ 66						$ 183
Basic earnings per share (usd per share)	$ 0.35						$ 0.97
Diluted earnings per share (usd per share)	$ 0.35						$ 0.97
ASU 2014-09
Statement of Financial Position [Abstract]
Retained deficit									13
ASU 2014-09 | Adjustments
Statement of Financial Position [Abstract]
Accounts receivable, net	$ 37						$ 37		(33)
Inventories, net	(15)						(15)		14
Deferred income taxes	(6)						(6)		6
Accrued expenses and other liabilities	(1)						(1)
Retained deficit	(15)						(15)		$ 13
Statement of Comprehensive Income [Abstract]
Sales	(10)						(34)
Cost of sales	(14)						(42)
Gross profit	4						8
Selling, general and administrative expenses	3						6
Equity and other income, net	1						1
Operating income	2						3
Income before income taxes	2						3
Income tax expense	1						1
Net income	$ 1						$ 2
Basic earnings per share (usd per share)	$ 0.01						$ 0.01
Diluted earnings per share (usd per share)	$ 0.01						$ 0.01