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, 2015	Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2012
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	$ 212,379	$ 263,082	$ 198,818	$ 301,792
Short-Term Investments	28,900	20,186
State And Municipal Bond Obligations [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	0	0
Short-Term Investments	20,417	20,186
US Treasury Bonds [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	0	0
Short-Term Investments	3,094	0
US Government Agency Bonds [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	0	0
Short-Term Investments	1,641	0
Corporate Bonds [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	0	0
Short-Term Investments	3,748	0
Cash [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	186,241	195,189
Short-Term Investments	0	0
Money Market Funds [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	26,138	67,893
Short-Term Investments	$ 0	$ 0