Restructuring Charges (Narrative) (Details)
 3 Months Ended 6 Months Ended
May 31, 2016
USD ($)
Nov. 30, 2015
USD ($)
Segments
May 31, 2015
USD ($)
facility
May 31, 2016
USD ($)
May 31, 2015
USD ($)
Restructuring Cost and Reserve [Line Items]          
Restructuring expenses $ 331,000   $ 3,810,000 $ 265,000 $ 6,153,000
Restructuring reserve 1,167,000 $ 3,361,000   1,167,000  
2015 Restructuring Activities [Member]          
Restructuring Cost and Reserve [Line Items]          
Number of facilities closed | facility     2    
Restructuring expenses 100,000     (22,000)  
Restructuring reserve 812,000 $ 2,617,000   812,000  
Number of operating segments | Segments   3      
2015 Restructuring Activities [Member] | Other accrued liabilities [Member]          
Restructuring Cost and Reserve [Line Items]          
Restructuring reserve 800,000     800,000  
2012 - 2014 Restructuring Activities [Member]          
Restructuring Cost and Reserve [Line Items]          
Restructuring expenses     $ 0   1,300,000
2012 - 2014 Restructuring Activities [Member] | Other accrued liabilities [Member]          
Restructuring Cost and Reserve [Line Items]          
Restructuring reserve 100,000     100,000  
Level 3 [Member] | Nonrecurring Basis [Member]          
Restructuring Cost and Reserve [Line Items]          
Long-lived assets at fair value     100,000   100,000
Telerik AD [Member]          
Restructuring Cost and Reserve [Line Items]          
Impairment of long-lived assets     4,000,000    
Telerik AD [Member] | 2015 Restructuring Activities [Member]          
Restructuring Cost and Reserve [Line Items]          
Restructuring expenses 200,000   $ 3,900,000 274,000 $ 4,900,000
Restructuring reserve 258,000 $ 518,000   258,000  
Telerik AD [Member] | 2015 Restructuring Activities [Member] | Other accrued liabilities [Member]          
Restructuring Cost and Reserve [Line Items]          
Restructuring reserve $ 300,000     $ 300,000