Quarterly Results (Unaudited) - Additonal Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Schedule of Quarterly Financial Information [Line Items]
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	$ (37.3)	$ (7.8)	$ 40.8	$ (49.8)
Net sales	766.1	756.4	1,412.6	1,358.7
Consolidated segment revenues	766.1	757.4	1,412.6	1,359.7
Operating income	28.9	95.3	55.5	136.6
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	0.7	(43.6)	501.5	259.2
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent	(37.5)	(24.4)	(8.7)	(71.6)
Net (loss) income attributable to common and participating preferred stockholders	(37.1)	(82.1)	470.3	130.1
Net (loss) income attributable to controlling interest	$ (37.1)	$ (82.1)	$ 470.3	$ 130.1
Income (Loss) from Continuing Operations, Per Basic Share	$ (0.18)	$ (0.12)	$ (0.04)	$ (0.36)
Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Basic Share	$ 0.00	$ (0.29)	$ 2.38	$ 1.01
Net income	$ (36.6)	$ (51.4)	$ 542.3	$ 209.4
Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Diluted Share	$ 0.00	$ (0.29)	$ 2.38	$ 1.01
Earnings Per Share, Diluted	$ (0.18)	$ (0.41)	$ 2.34	$ 0.65
Discontinued Operations, Held-for-sale [Member]
Schedule of Quarterly Financial Information [Line Items]
Consolidated segment revenues				$ 0.0
Operating income			$ 0.0	0.0
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest			459.9	187.7
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	$ 0.4	$ (57.7)
Net (loss) income attributable to controlling interest			454.5	160.2
Net income			$ 459.9	$ 187.7