Restructuring Charges (Narrative) (Details)	3 Months Ended			9 Months Ended
	Aug. 31, 2016 USD ($)	Nov. 30, 2015 USD ($) Segments	Aug. 31, 2015 USD ($) facility	Aug. 31, 2016 USD ($)	Aug. 31, 2015 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	$ (36,000)		$ 2,561,000	$ 229,000	$ 8,715,000
Restructuring reserve	613,000	$ 3,361,000		613,000
2015 Restructuring Activities [Member]
Restructuring Cost and Reserve [Line Items]
Number of facilities closed | facility			2
Restructuring expenses				(42,000)
Restructuring reserve	371,000	$ 2,617,000		371,000
Number of operating segments | Segments		3
2015 Restructuring Activities [Member] | Other accrued liabilities [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	400,000			400,000
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			$ 2,500,000	280,000	$ 7,400,000
Restructuring reserve	180,000	$ 518,000		180,000
Telerik AD [Member] | 2015 Restructuring Activities [Member] | Other accrued liabilities [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	$ 200,000			$ 200,000