Cash, Cash Equivalents and Investments (Summary of Cash, Cash Equivalents and Available-for-sale Investments by Balance Sheet Classification) (Details) - USD ($) $ in Thousands	Aug. 31, 2020	Nov. 30, 2019
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	$ 220,575	$ 154,259
Short-Term Investments	9,544	19,426
State and municipal bond obligations
Cash, Cash Equivalents and Investments [Line Items]
Short-Term Investments		7,037
U.S. treasury bonds
Cash, Cash Equivalents and Investments [Line Items]
Short-Term Investments	5,069	7,231
Corporate bonds
Cash, Cash Equivalents and Investments [Line Items]
Short-Term Investments	4,475	5,158
Cash
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	214,037	144,346
Money market funds
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	$ 6,538	$ 9,913