Unconsolidated Significant Subsidiary (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Equity Method Investments and Joint Ventures [Abstract]
Sales	$ 71	$ 83	$ 143	$ 168
Gross margin	18	21	38	43
Income from continuing operations	11	13	23	29
Net income	$ 11	$ 13	$ 23	$ 29