Segment Information and Sales to Significant Customers - Revenue and Customer Information (Detail) - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Revenue from External Customer [Line Items]
Total revenue	$ 3,643,538	$ 3,563,637	$ 3,345,854
Customer Experience Solutions [Member]
Revenue from External Customer [Line Items]
Total revenue	3,542,531	3,435,478	3,185,637
Directory [Member]
Revenue from External Customer [Line Items]
Total revenue	$ 101,007	$ 128,159	$ 160,217

Revenue from multiple-deliverable arrangements that include licensing fees and services revenue. Licensing revenue is consideration received from another party for the right to use, but not own, certain of the entity's intangible assets. Licensing arrangements include, but are not limited to, rights to use a patent, copyright, technology, manufacturing process, software or trademark. Licensing fees are generally, but not always, fixed as to amount and not dependent upon the revenue generated by the licensing party. An entity may receive licensing fees for licenses that also generate royalty payments to the entity. Services revenue may be derived by providing other, nonspecified, services during the reporting period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1(d),(e))
-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 1
-Article 5

Name:	us-gaap_LicenseAndServicesRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration