Goodwill And Intangible Assets (Components Of Intangible Assets) (Details) - USD ($) $ in Thousands	9 Months Ended
Jun. 30, 2018	Sep. 30, 2017
Finite-Lived Intangible Assets
Weighted-Average Life (years)	12 years
Gross Carrying Amount	$ 316,234	$ 345,185
Accumulated Amortization	$ (203,396)	(236,367)
Customer-Related
Finite-Lived Intangible Assets
Weighted-Average Life (years)	11 years
Gross Carrying Amount	$ 148,558	175,872
Accumulated Amortization	$ (97,083)	(128,019)
Technology-Related
Finite-Lived Intangible Assets
Weighted-Average Life (years)	10 years
Gross Carrying Amount	$ 72,722	71,924
Accumulated Amortization	$ (50,766)	(55,069)
Program-Related
Finite-Lived Intangible Assets
Weighted-Average Life (years)	19 years
Gross Carrying Amount	$ 65,676	66,458
Accumulated Amortization	$ (33,168)	(30,675)
Marketing-Related
Finite-Lived Intangible Assets
Weighted-Average Life (years)	8 years
Gross Carrying Amount	$ 24,945	26,552
Accumulated Amortization	$ (18,842)	(19,251)
Other Intangible Assets
Finite-Lived Intangible Assets
Weighted-Average Life (years)	10 years
Gross Carrying Amount	$ 4,333	4,379
Accumulated Amortization	$ (3,537)	$ (3,353)

Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_CustomerRelatedIntangibleAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_TechnologyBasedIntangibleAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_CustomerContractsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_MarketingRelatedIntangibleAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_OtherIntangibleAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: