Restructuring Charges (Summary of Restructuring Activity) (Details) - USD ($) $ in Thousands	3 Months Ended
	Feb. 29, 2020	Feb. 28, 2019
Restructuring Reserve [Roll Forward]
Beginning Balance	$ 2,203
Costs incurred	1,040	$ 415
Cash disbursements	(1,429)
Translation adjustments and other	(24)
Ending Balance	1,790
2019 Restructuring Activities
Restructuring Reserve [Roll Forward]
Beginning Balance	1,460
Costs incurred	(9)
Cash disbursements	(844)
Translation adjustments and other	0
Ending Balance	607
2019 Restructuring Activities | Ipswitch
Restructuring Reserve [Roll Forward]
Beginning Balance	552
Costs incurred	1,036
Cash disbursements	(547)
Translation adjustments and other	(24)
Ending Balance	1,017
Excess Facilities and Other Costs
Restructuring Reserve [Roll Forward]
Beginning Balance	196
Costs incurred	1,010
Cash disbursements	(160)
Translation adjustments and other	(24)
Ending Balance	1,022
Excess Facilities and Other Costs | 2019 Restructuring Activities
Restructuring Reserve [Roll Forward]
Beginning Balance	0
Costs incurred	0
Cash disbursements	0
Translation adjustments and other	0
Ending Balance	0
Excess Facilities and Other Costs | 2019 Restructuring Activities | Ipswitch
Restructuring Reserve [Roll Forward]
Beginning Balance	5
Costs incurred	997
Cash disbursements	(123)
Translation adjustments and other	(24)
Ending Balance	855
Employee Severance and Related Benefits
Restructuring Reserve [Roll Forward]
Beginning Balance	2,007
Costs incurred	30
Cash disbursements	(1,269)
Translation adjustments and other	0
Ending Balance	768
Employee Severance and Related Benefits | 2019 Restructuring Activities
Restructuring Reserve [Roll Forward]
Beginning Balance	1,460
Costs incurred	(9)
Cash disbursements	(844)
Translation adjustments and other	0
Ending Balance	607
Employee Severance and Related Benefits | 2019 Restructuring Activities | Ipswitch
Restructuring Reserve [Roll Forward]
Beginning Balance	547
Costs incurred	39
Cash disbursements	(424)
Translation adjustments and other	0
Ending Balance	$ 162