Cash, Cash Equivalents and Investments (Summary Of Cash, Cash Equivalents And Available-For-Sale Investments) (Details) - USD ($) $ in Thousands	Aug. 31, 2019	Nov. 30, 2018
Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	$ 124,020	$ 105,126	[1]
Unrealized Gains	38	0
Unrealized Losses	0	(210)
Total Amortized Cost Basis	145,359	139,723
Total Fair Value	145,397	139,513
State and municipal bond obligations
Cash, Cash Equivalents and Investments [Line Items]
Amortized Cost Basis	8,300	19,542
Unrealized Gains	3	0
Unrealized Losses	0	(119)
Fair Value	8,303	19,423
U.S. treasury bonds
Cash, Cash Equivalents and Investments [Line Items]
Amortized Cost Basis	6,860	6,726
Unrealized Gains	21	0
Unrealized Losses	0	(21)
Fair Value	6,881	6,705
Corporate bonds
Cash, Cash Equivalents and Investments [Line Items]
Amortized Cost Basis	6,179	8,329
Unrealized Gains	14	0
Unrealized Losses	0	(70)
Fair Value	6,193	8,259
Cash
Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	116,146	101,316
Money market funds
Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	$ 7,874	$ 3,810

[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 Basis of Presentation for further information.