Cash, Cash Equivalents and Investments (Fair Value of Debt Securities by Contractual Maturity) (Details) - USD ($) $ in Thousands |
May. 31, 2015 |
Nov. 30, 2014 |
|---|---|---|
| Investments and Cash [Abstract] | ||
| Due in one year or less | $ 10,384 | $ 11,140 |
| Due after one year | 22,717 | 9,046 |
| Total | $ 33,101 | $ 20,186 |