Derivatives and Hedging Activities (Details) - Designated as Hedging Instrument [Member] - Cash Flow Hedging [Member] - Cross Currency Interest Rate Swaps [Member] £ in Millions, $ in Millions	12 Months Ended
Sep. 30, 2018 USD ($) Instruments	Sep. 30, 2018 GBP (£) Instruments
Number of Instruments \| Instruments	1	1
Receive Floating Notional \| $	$ 46.7
GBP [Member]
Pay Fixed Notional \| £		£ 36.6

The number of derivative instruments of a particular group held by the entity.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5579245-113959

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5580258-113959

Name:	us-gaap_DerivativeNumberOfInstrumentsHeld
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant