Cash, Cash Equivalents and Investments (Summary Of Cash, Cash Equivalents And Available-For-Sale Investments) (Details) - USD ($) $ in Thousands	May 31, 2020	Nov. 30, 2019
Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	$ 193,222	$ 154,259
Unrealized Gains	152	23
Unrealized Losses	0	0
Total Amortized Cost Basis	203,493	173,662
Total Fair Value	203,645	173,685
State and municipal bond obligations
Cash, Cash Equivalents and Investments [Line Items]
Amortized Cost Basis		7,036
Unrealized Gains		1
Unrealized Losses		0
Fair Value		7,037
U.S. treasury bonds
Cash, Cash Equivalents and Investments [Line Items]
Amortized Cost Basis	4,994	7,221
Unrealized Gains	89	10
Unrealized Losses	0	0
Fair Value	5,083	7,231
Corporate bonds
Cash, Cash Equivalents and Investments [Line Items]
Amortized Cost Basis	5,277	5,146
Unrealized Gains	63	12
Unrealized Losses	0	0
Fair Value	5,340	5,158
Cash
Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	187,573	144,346
Money market funds
Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	$ 5,649	$ 9,913