CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Net sales	$ 2,036.9	$ 1,747.5	$ 4,866.6	$ 4,523.8
Cost of sales	1,650.0	1,432.9	4,018.7	3,767.1
Gross income	386.9	314.6	847.9	756.7
Operating expenses:
Selling, general and administrative	163.9	154.7	484.7	448.7
Amortization of purchased intangibles	11.1	13.1	34.7	39.5
Total operating expenses	175.0	167.8	519.4	488.2
Operating income	211.9	146.8	328.5	268.5
Other income (expense):
Interest expense	(15.3)	(15.8)	(45.1)	(46.0)
Interest income	1.4	0.5	3.2	1.5
Miscellaneous, net	0.6	0.8	3.1	(0.2)
Income before income taxes and equity in earnings of unconsolidated affiliates	198.6	132.3	289.7	223.8
Provision for income taxes	70.1	48.4	98.9	70.4
Income before equity in earnings of unconsolidated affiliates	128.5	83.9	190.8	153.4
Equity in earnings of unconsolidated affiliates	0.1	0.3	1.3	1.5
Net income	$ 128.6	$ 84.2	$ 192.1	$ 154.9
Earnings per share attributable to common shareholders:
Basic earnings per share (in dollars per share)	$ 1.72	$ 1.15	$ 2.57	$ 2.11
Diluted earnings per share (in dollars per share)	1.69	1.13	2.54	2.08
Cash dividends declared per share on common stock (in dollars per share)	$ 0.21	$ 0.19	$ 0.63	$ 0.57