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, unless otherwise specified	Aug. 31, 2014	Nov. 30, 2013	Aug. 31, 2013	Nov. 30, 2012
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	$ 242,380	$ 198,818	$ 215,342	$ 301,792
Short-Term Investments	18,912	32,622
Long-Term Investments	0	24,761
State and municipal bond obligations [Member]
Cash, Cash Equivalents and Investments [Line Items]
Short-Term Investments	18,912	31,102
Long-Term Investments	0	0
Auction rate securities - municipal bonds [Member]
Cash, Cash Equivalents and Investments [Line Items]
Short-Term Investments	0	1,520
Long-Term Investments	0	21,933
Auction rate securities - student loans [Member]
Cash, Cash Equivalents and Investments [Line Items]
Short-Term Investments	0	0
Long-Term Investments	0	2,828
Cash [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	173,237	144,305
Money market funds [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and Equivalents	$ 69,143	$ 54,513