Business Combinations (Narrative) (Details) - USD ($)		3 Months Ended		6 Months Ended
	Dec. 02, 2014	May 31, 2016	May 31, 2015	May 31, 2016	May 31, 2015
Business Acquisition [Line Items]
Acquisition-related costs		$ 324,000	$ 1,010,000	$ 396,000	$ 2,518,000
Total revenue		96,118,000	88,817,000	185,599,000	170,198,000
Income (loss) before income taxes		10,983,000	(3,760,000)	15,863,000	(14,014,000)
Intangible assets, amortization expense		7,100,000	7,300,000	14,300,000	15,100,000
Stock-based compensation expense		6,293,000	6,439,000	13,231,000	12,275,000
Telerik AD [Member]
Business Acquisition [Line Items]
Total purchase consideration	$ 262,500,000
Total consideration paid to founders and key employees in restricted stock units	$ 10,500,000
Percent of total consideration deposited into escrow	10.00%
Acquisition-related costs		300,000	1,100,000	300,000	1,900,000
Earn-out provision	$ 2,200,000
Service period	1 year
Expense recognized related to contingent earn-out provisions		0	600,000	0	1,200,000
Total revenue		18,500,000	9,200,000	36,600,000	13,700,000
Income (loss) before income taxes		(7,600,000)	(14,000,000)	(13,000,000)	(31,000,000)
Intangible assets, amortization expense		6,200,000	$ 6,200,000	12,300,000	$ 12,300,000
Stock-based compensation expense		$ 2,100,000		$ 4,200,000
Credit Agreement [Member]
Business Acquisition [Line Items]
Term loan	$ 150,000,000