Cash, Cash Equivalents and Investments (Fair Value of Debt Securities by Contractual Maturity) (Details) - USD ($) $ in Thousands |
May 31, 2016 |
Nov. 30, 2015 |
|---|---|---|
| Investments and Cash [Abstract] | ||
| Due in one year or less | $ 27,380 | $ 15,945 |
| Due after one year | 21,996 | 12,955 |
| Total | $ 49,376 | $ 28,900 |