Derivative Financial Instruments (Amounts Recognized in AOCI) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized derivative (loss) gain on cash flow hedges, net of tax	$ (4,717)	$ 74	$ (21)
Other Comprehensive Income (Loss) [Member] | Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized derivative (loss) gain on cash flow hedges, net of tax	(5,375)	(424)	(118)
Interest Rate Swap [Member] | Other Comprehensive Income (Loss) [Member] | Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(5,155)	0	0
Interest Rate Cap [Member] | Other Comprehensive Income (Loss) [Member] | Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(19)	19	0
Foreign Exchange Forward [Member] | Other Comprehensive Income (Loss) [Member] | Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	$ (201)	$ (443)	$ (118)