Earnings Per Share (Calculation of Basic and Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Nov. 30, 2019	Aug. 31, 2019	May 31, 2019	Feb. 28, 2019	Nov. 30, 2018	Aug. 31, 2018	May 31, 2018	Feb. 28, 2018	Nov. 30, 2019	Nov. 30, 2018		Nov. 30, 2017
Earnings Per Share [Abstract]
Net income	$ (4,740)	$ 13,557	$ 8,181	$ 9,402	$ 8,644	$ 14,390	$ 12,904	$ 13,732	$ 26,400	$ 49,670	[1],[2],[3]	$ 29,021	[1],[2],[3]
Weighted average shares outstanding (in shares)									44,791	45,561	[1]	48,129	[1]
Dilutive impact from common stock equivalents (in shares)									549	574		387
Diluted weighted average shares outstanding (in shares)									45,340	46,135	[1]	48,516	[1]
Basic earnings (loss) per share (in dollars per share)	$ (0.11)	$ 0.30	$ 0.18	$ 0.21	$ 0.19	$ 0.32	$ 0.28	$ 0.30	$ 0.59	$ 1.09	[1]	$ 0.60	[1]
Diluted earnings (loss) per share (in dollars per share)	$ (0.11)	$ 0.30	$ 0.18	$ 0.21	$ 0.19	$ 0.32	$ 0.28	$ 0.29	$ 0.58	$ 1.08	[1]	$ 0.60	[1]

[1] The Company adopted the accounting standard related to revenue recognition ("ASC 606") effective December 1, 2018 using the full retrospective method. See Note 1. Nature of Business and Summary of Significant Accounting Policies for further information.

[2] The Company adopted the accounting standard related to revenue recognition ("ASC 606") effective December 1, 2018 using the full retrospective method. See Note 1. Nature of Business and Summary of Significant Accounting Policies for further information.

[3] The Company adopted the accounting standard related to revenue recognition ("ASC 606") effective December 1, 2018 using the full retrospective method. See Note 1. Nature of Business and Summary of Significant Accounting Policies for further information.