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	Nov. 30, 2016	Nov. 30, 2015	Nov. 30, 2014	Nov. 30, 2013
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	$ 207,036	$ 212,379	$ 263,082	$ 198,818
Short-Term Investments	42,718	28,900
State and Municipal Bond Obligations [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	0	0
Short-Term Investments	32,724	20,417
US Treasury Bonds [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	0	0
Short-Term Investments	6,513	3,094
US Government Agency Bonds [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	0	0
Short-Term Investments	0	1,641
Corporate Bonds [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	0	0
Short-Term Investments	3,481	3,748
Cash [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	196,863	186,241
Short-Term Investments	0	0
Money Market Funds [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	10,173	26,138
Short-Term Investments	$ 0	$ 0