Segment Reporting - Additional Information (Detail) (USD $) In Thousands	3 Months Ended	9 Months Ended
Aug. 31, 2011	Aug. 31, 2010	Aug. 31, 2011	Aug. 31, 2010
Segment Reporting Disclosure [Line Items]
Revenues	$ 150,813	$ 160,675	$ 439,349	$ 456,038
Intersegment Elimination
Segment Reporting Disclosure [Line Items]
Revenues	$ 500	$ 500	$ 1,600	$ 1,700

Amount of total revenue for the reportable segments, including revenue from external customers, transactions with other operating segments of the same entity, and (gross) interest revenue. All considered to be "operating revenue" for purposes of the taxonomy.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 131
-Paragraph 27
-Subparagraph a, b, c
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-Subparagraph (a),(b),(c)
-URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e8736-108599

Name:	us-gaap_SegmentReportingInformationRevenue
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration