Restructuring Charges (Narrative) (Details) - USD ($)	3 Months Ended			6 Months Ended
	May 31, 2017	Feb. 28, 2017	May 31, 2016	May 31, 2017	May 31, 2016	Nov. 30, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	$ 662,000		$ 331,000	$ 17,801,000	$ 265,000
Restructuring reserve	7,212,000			7,212,000		$ 1,550,000
2017 Restructuring Activities [Member]
Restructuring Cost and Reserve [Line Items]
Global workforce reduction (as a percent)		20.00%
Restructuring expenses	600,000			17,724,000
Restructuring reserve	6,559,000			6,559,000		0
2017 Restructuring Activities [Member] | Other accrued liabilities [Member]
Restructuring Cost and Reserve [Line Items]
Short-term portion of restructuring reserve	6,300,000			6,300,000
2017 Restructuring Activities [Member] | Other Noncurrent Liabilities [Member]
Restructuring Cost and Reserve [Line Items]
Long-term portion of restructuring reserve	300,000			300,000
2016 Restructuring Activities [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	0			0
Restructuring reserve	$ 589,000			$ 589,000		$ 1,415,000