Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data	Aug. 31, 2011	Nov. 30, 2010
Allowance for receivables	$ 1,000	$ 1,200
Property and Equipment, accumulated depreciation	$ 635,034	$ 589,285
Class A Common Stock $.01 Par Value
Common Stock, par value	$ 0.01	$ 0.01
Common Stock, shares authorized	80,000,000	80,000,000
Common Stock, shares issued	27,037,622	27,531,352
Common Stock, shares outstanding	27,037,622	27,531,352
Class B Common Stock $.01 Par Value
Common Stock, par value	$ 0.01	$ 0.01
Common Stock, shares authorized	40,000,000	40,000,000
Common Stock, shares issued	20,155,851	20,373,199
Common Stock, shares outstanding	20,155,851	20,373,199