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 |
May. 31, 2015 |
Nov. 30, 2014 |
May. 31, 2014 |
Nov. 30, 2013 |
|---|---|---|---|---|
| Cash, Cash Equivalents and Investments [Line Items] | ||||
| Cash and Equivalents | $ 166,020 | $ 263,082 | $ 201,971 | $ 198,818 |
| Short-Term Investments | 33,101 | 20,186 | ||
| State and municipal bond obligations [Member] | ||||
| Cash, Cash Equivalents and Investments [Line Items] | ||||
| Short-Term Investments | 33,101 | 20,186 | ||
| Cash [Member] | ||||
| Cash, Cash Equivalents and Investments [Line Items] | ||||
| Cash and Equivalents | 144,175 | 195,189 | ||
| Money market funds [Member] | ||||
| Cash, Cash Equivalents and Investments [Line Items] | ||||
| Cash and Equivalents | $ 21,845 | $ 67,893 |