Other Comprehensive Income (Schedule of Items Reclassified out of AOCL) (Details) - USD ($)	3 Months Ended								12 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net									$ 700,000
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax									(4,200,000)	$ (2,000,000.0)	$ 6,000,000.0
Tax effect 5									56,400,000	(55,200,000)	50,700,000
Net of tax	$ (27,900,000)	$ (32,600,000)	$ (49,500,000)	$ (42,200,000)	$ (90.4)	$ (45.2)	$ (28.5)	$ (88.3)	(152,200,000)	(252,400,000)	(133,600,000)
Retained Earnings [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification									5,400,000
Net of tax											(133,600,000)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax									6,200,000	5,000,000.0	(900,000)
Net of tax									(4,800,000)	(3,800,000)	(600,000)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax									0	0	(1,000,000.0)
Change in Pension and Postretirement Defined Benefit Plans [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification									(6,200,000)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax									(2,000,000.0)	3,000,000.0	(5,900,000)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Tax effect 5									1,400,000	1,200,000	300,000
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Tax effect 5									0	0	0
Net of tax									0	0	(1,000,000.0)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Change in Pension and Postretirement Defined Benefit Plans [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Tax effect 5									(2,400,000)	(1,000,000.0)	(2,200,000)
Net of tax									400,000	(2,000,000.0)	(3,700,000)
Foreign Exchange Forward [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Tax effect 5											0
Foreign Exchange Forward [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax									600,000	(300,000)	(200,000)
Tax effect 5									(200,000)	0
Net of tax									(400,000)	300,000	200,000
Interest Rate Swap [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Tax effect 5											300,000
Interest Rate Swap [Member] | Retained Earnings [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification									800,000
Interest Rate Swap [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax									(6,800,000)	5,300,000	(700,000)
Tax effect 5									1,600,000	1,200,000
Net of tax									$ 5,200,000	$ 4,100,000	$ 400,000