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	Feb. 29, 2016	Nov. 30, 2015	Feb. 28, 2015	Nov. 30, 2014
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	$ 203,704	$ 212,379	$ 187,035	$ 263,082
Short-Term Investments	47,787	28,900
State and municipal bond obligations [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	0	0
Short-Term Investments	38,295	20,417
U.S. treasury bonds [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	0	0
Short-Term Investments	4,105	3,094
U.S. government agency bonds [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	0	0
Short-Term Investments	1,638	1,641
Corporate bonds [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	0	0
Short-Term Investments	3,749	3,748
Cash [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	196,422	186,241
Short-Term Investments	0	0
Money market funds [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	7,282	26,138
Short-Term Investments	$ 0	$ 0