Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

No definition available.

Name:	us-gaap_NumberOfOperatingSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Organization and Basis of Presentation (Detail)		12 Months Ended
Organization and Basis of Presentation (Detail)	Nov. 22, 2017	Nov. 30, 2017 USD ($) segment	Nov. 30, 2016 USD ($)	Nov. 30, 2015 USD ($)
Organization And Basis Of Presentation [Line Items]
Debt called amount			$ 350,000,000	$ 500,000,000
Redemption price as percentage of principal amount redeemed	100.00%
Number of operating segments \| segment		2
3.875% Convertible Senior Debentures due 2029
Organization And Basis Of Presentation [Line Items]
Debt instrument interest rate		3.875%
Aggregate principal amount of debt issued		$ 345,000,000.0
Debt called amount		$ 20,200,000