Stockholders' Equity (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended												12 Months Ended
	Nov. 30, 2012	Aug. 31, 2012	May 31, 2012	Feb. 29, 2012	Nov. 30, 2011	Aug. 31, 2011	May 31, 2011	Feb. 28, 2011	Nov. 30, 2010	Aug. 31, 2010	May 31, 2010	Feb. 28, 2010	Nov. 30, 2012	Nov. 30, 2011	Nov. 30, 2010
Stockholder's Equity (Textual) [Abstract]
Number of shares that can be purchased by exercising each right	0.01												0.01
Purchase price for right holders	$ 85.00												$ 85.00
Exercisable options available													earlier of (i) 10 calendar days after a public announcement by us that a person or group has become an Acquiring Person (as defined under the 2009 Rights Agreement) and (ii) 10 business days after the commencement of a tender or exchange offer by a person or group if upon consummation of the offer the person or group would beneficially own 4.9% or more of our outstanding common stock.
Calendar days after a public announcement during which rights to be exercised													10 days
Business days after the commencement of a tender or exchange offer during which rights to be exercised													10 days
Beneficially ownership in company's outstanding common stock to be held by person or group to exercise rights													4.90%
Price at which company may redeem all of the then outstanding rights	0.001												0.001
Options under which right issued pursuant to the 2009 rights Agreement will expire													earliest of (a) the close of business on March 5, 2019, (b) the time at which the rights are redeemed, (c) the time at which the rights are exchanged, (d) the time at which our board of directors determines that a related provision in our Restated Certificate of Incorporation is no longer necessary, and (e) the close of business on the first day of a taxable year of ours to which our board of directors determines that no tax benefits may be carried forward. At our annual meeting of stockholders on April 2, 2009, our stockholders approved the 2009 Rights Agreement.
Authorized repurchase of common stock	4,000,000												4,000,000
Cash dividend declared per share	$ 0.025	$ 0.025	$ 0.0250	$ 0.0625	$ 0.0625	$ 0.0625	$ 0.0625	$ 0.0625	$ 0.0625	$ 0.0625	$ 0.0625	$ 0.0625
Repurchases of common stock													$ (1,799)	$ 0	$ (350)