Segment and Geographic Information and Significant Customers (Classification of Revenue by Major Geographic Areas) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Dec. 31, 2013	Dec. 31, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 490,045	$ 492,417
Total revenues	469,980	462,268
UNITED STATES
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	343,185	340,288
International [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 126,795	$ 121,980

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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)

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