Credit Facilities and Debt Credit Facilities and Debt - Credit Facilities Margin for Borrowings Table (Details) - Revolving Credit Facility Due March Thirty One Twenty Fifteen [Member]	12 Months Ended
	Sep. 30, 2019
Maximum | Base Rate [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.75%
Maximum | London Interbank Offered Rate [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.75%
Minimum | Base Rate [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.50%
Minimum | London Interbank Offered Rate [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.50%