Restructuring (Summary of Restructuring Activity) (Details) - USD ($) $ in Thousands	12 Months Ended
	Nov. 30, 2019	Nov. 30, 2018	Nov. 30, 2017
Restructuring Reserve [Roll Forward]
Beginning Balance	$ 311	$ 4,126	$ 1,550
Costs incurred	6,331	2,251	22,210
Cash disbursements	(4,407)	(6,111)	(19,234)
Asset impairment			(762)
Translation adjustments and other	(32)	45	362
Ending Balance	2,203	311	4,126
Excess Facilities and Other Costs
Restructuring Reserve [Roll Forward]
Beginning Balance	307	570	107
Costs incurred	740	1,011	2,655
Cash disbursements	(760)	(1,309)	(1,456)
Asset impairment			(762)
Translation adjustments and other	(91)	35	26
Ending Balance	196	307	570
Employee Severance and Related Benefits
Restructuring Reserve [Roll Forward]
Beginning Balance	4	3,556	1,443
Costs incurred	5,591	1,240	19,555
Cash disbursements	(3,647)	(4,802)	(17,778)
Asset impairment			0
Translation adjustments and other	59	10	336
Ending Balance	2,007	4	3,556
2019 Restructuring Activities
Restructuring Reserve [Roll Forward]
Beginning Balance	0
Costs incurred	2,494
Cash disbursements	(1,035)
Translation adjustments and other	1
Ending Balance	1,460	0
2019 Restructuring Activities | Excess Facilities and Other Costs
Restructuring Reserve [Roll Forward]
Beginning Balance	0
Costs incurred	0
Cash disbursements	0
Translation adjustments and other	0
Ending Balance	0	0
2019 Restructuring Activities | Employee Severance and Related Benefits
Restructuring Reserve [Roll Forward]
Beginning Balance	0
Costs incurred	2,494
Cash disbursements	(1,035)
Translation adjustments and other	1
Ending Balance	1,460	0
2017 Restructuring Activities
Restructuring Reserve [Roll Forward]
Beginning Balance	311	4,096	0
Costs incurred	739	2,251	22,125
Cash disbursements	(768)	(6,081)	(17,629)
Asset impairment	(89)		(762)
Translation adjustments and other	(2)	45	362
Ending Balance	191	311	4,096
2017 Restructuring Activities | Excess Facilities and Other Costs
Restructuring Reserve [Roll Forward]
Beginning Balance	307	540	0
Costs incurred	735	1,011	2,570
Cash disbursements	(760)	(1,279)	(1,294)
Asset impairment	(89)		(762)
Translation adjustments and other	(2)	35	26
Ending Balance	191	307	540
2017 Restructuring Activities | Employee Severance and Related Benefits
Restructuring Reserve [Roll Forward]
Beginning Balance	4	3,556	0
Costs incurred	4	1,240	19,555
Cash disbursements	(8)	(4,802)	(16,335)
Asset impairment	0		0
Translation adjustments and other	0	10	336
Ending Balance	0	4	$ 3,556
Ipswitch | 2019 Restructuring Activities
Restructuring Reserve [Roll Forward]
Beginning Balance	0
Costs incurred	3,098
Cash disbursements	(2,604)
Translation adjustments and other	58
Ending Balance	552	0
Ipswitch | 2019 Restructuring Activities | Excess Facilities and Other Costs
Restructuring Reserve [Roll Forward]
Beginning Balance	0
Costs incurred	5
Cash disbursements	0
Translation adjustments and other	0
Ending Balance	5	0
Ipswitch | 2019 Restructuring Activities | Employee Severance and Related Benefits
Restructuring Reserve [Roll Forward]
Beginning Balance	0
Costs incurred	3,093
Cash disbursements	(2,604)
Translation adjustments and other	58
Ending Balance	$ 547	$ 0