Derivative Financial Instruments (Amounts Recognized in AOCI) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized derivative gain (loss) on cash flow hedges, net of tax	$ 7,293	$ (4,717)	$ 74
Other Comprehensive Income (Loss) | Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized derivative gain (loss) on cash flow hedges, net of tax	4,909	(5,375)	(424)
Interest rate swaps | Other Comprehensive Income (Loss) | Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized derivative gain (loss) on cash flow hedges, net of tax	5,252	(5,155)	0
Interest rate cap | Other Comprehensive Income (Loss) | Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized derivative gain (loss) on cash flow hedges, net of tax	0	(19)	19
Foreign currency forward contracts | Other Comprehensive Income (Loss) | Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized derivative gain (loss) on cash flow hedges, net of tax	(324)	(201)	(443)
Commodity swaps | Other Comprehensive Income (Loss) | Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized derivative gain (loss) on cash flow hedges, net of tax	$ (19)	$ 0	$ 0