Business Segments and International Operations (Narrative) (Details) (USD $) In Thousands, 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, 2012	Nov. 30, 2011	Nov. 30, 2010
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 91,271	$ 78,317	$ 78,404	$ 87,213	$ 93,544	$ 88,681	$ 90,955	$ 87,524	$ 335,205	$ 360,704	$ 351,610
Criteria for major customers, percentage of revenue									10.00%
Long-lived assets	63,071				66,206				63,071	66,206
Criteria for major customers, percentage of long-lived assets									10.00%
United Kingdom [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									35,700	43,400	39,700
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	57,900				59,600				57,900	59,600	54,700
Outside United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 5,200				$ 6,600				$ 5,200	$ 6,600	$ 7,800