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, 2016 |
Nov. 30, 2015 |
May 31, 2015 |
Nov. 30, 2014 |
| Cash, Cash Equivalents and Investments [Line Items] |
|
|
|
|
| Cash and Equivalents |
$ 179,733
|
$ 212,379
|
$ 166,020
|
$ 263,082
|
| Short-Term Investments |
49,376
|
28,900
|
|
|
| State and municipal bond obligations [Member] |
|
|
|
|
| Cash, Cash Equivalents and Investments [Line Items] |
|
|
|
|
| Cash and Equivalents |
0
|
0
|
|
|
| Short-Term Investments |
39,587
|
20,417
|
|
|
| U.S. treasury bonds [Member] |
|
|
|
|
| Cash, Cash Equivalents and Investments [Line Items] |
|
|
|
|
| Cash and Equivalents |
0
|
0
|
|
|
| Short-Term Investments |
4,652
|
3,094
|
|
|
| U.S. government agency bonds [Member] |
|
|
|
|
| Cash, Cash Equivalents and Investments [Line Items] |
|
|
|
|
| Cash and Equivalents |
0
|
0
|
|
|
| Short-Term Investments |
1,633
|
1,641
|
|
|
| Corporate bonds [Member] |
|
|
|
|
| Cash, Cash Equivalents and Investments [Line Items] |
|
|
|
|
| Cash and Equivalents |
0
|
0
|
|
|
| Short-Term Investments |
3,504
|
3,748
|
|
|
| Cash [Member] |
|
|
|
|
| Cash, Cash Equivalents and Investments [Line Items] |
|
|
|
|
| Cash and Equivalents |
174,198
|
186,241
|
|
|
| Short-Term Investments |
0
|
0
|
|
|
| Money market funds [Member] |
|
|
|
|
| Cash, Cash Equivalents and Investments [Line Items] |
|
|
|
|
| Cash and Equivalents |
5,535
|
26,138
|
|
|
| Short-Term Investments |
$ 0
|
$ 0
|
|
|