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	Nov. 30, 2012	Nov. 30, 2011	Nov. 30, 2010	Nov. 30, 2009
Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	$ 301,792	$ 161,095	$ 286,559	$ 175,873
Short-term Investments	53,425	100,321
Long-term Investments	26,321	33,539
Cash [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	176,201	134,890
Short-term Investments	0	0
Long-term Investments	0	0
Money Market Funds [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	125,591	24,220
Short-term Investments	0	0
Long-term Investments	0	0
State And Municipal Bond Obligations [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	0	1,985
Short-term Investments	50,818	82,413
Long-term Investments	0	0
Brazilian Mutual Funds [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	0	0
Short-term Investments	0	15,346
Long-term Investments	0	0
Auction Rate Securities - Municipal Bonds [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	0	0
Short-term Investments	0	0
Long-term Investments	23,420	22,931
Auction Rate Securities - Student Loans [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	0	0
Short-term Investments	0	0
Long-term Investments	2,901	10,608
Corporate Bonds [Member]
Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	0	0
Short-term Investments	2,607	2,562
Long-term Investments	$ 0	$ 0