Cash, Cash Equivalents and Investments (Summary of Cash, Cash Equivalents and Trading and Available-for-sale Investments by Balance Sheet Classification) (Details) - USD ($) $ in Thousands	Aug. 31, 2015	Nov. 30, 2014	Aug. 31, 2014	Nov. 30, 2013
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	$ 189,113	$ 263,082	$ 242,380	$ 198,818
Short-Term Investments	29,191	20,186
State and municipal bond obligations [Member]
Cash, Cash Equivalents and Investments [Line Items]
Short-Term Investments	29,191	20,186
Cash [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	163,248	195,189
Money market funds [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	$ 25,865	$ 67,893