Intangible Assets Subject to Amortization (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Sep. 30, 2016
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 363,815	$ 354,522
Accum. Amortization	269,295	256,866
Net	94,520	97,656
Customer Lists
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	334,605	327,388
Accum. Amortization	261,017	250,427
Net	73,588	76,961
Trade Names And Other Intangibles
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	29,210	27,134
Accum. Amortization	8,278	6,439
Net	$ 20,932	$ 20,695

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

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

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

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

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