Condensed Consolidated Statement of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Comprehensive income
Net income	$ 189.5	$ 168.0	$ 404.2	$ 353.5
Other comprehensive income (loss), net of tax:
Pension and other postretirement benefit plan adjustments (net of tax expense of $12.4, $9.8, $25.0, $19.6)	23.8	18.4	48.3	36.8
Currency translation adjustments	60.8	7.4	(25.4)	(17.0)
Net change in unrealized gains and losses on cash flow hedges (net of tax (benefit) expense of ($0.7), ($4.3), $3.3, and ($4.1))	(3.6)	(12.5)	8.0	(10.9)
Net change in unrealized gains and losses on available-for-sale investments	(0.1)	0.0	(0.1)	0.0
Other comprehensive income (loss)	80.9	13.3	30.8	8.9
Comprehensive income	$ 270.4	$ 181.3	$ 435.0	$ 362.4