Cash, Cash Equivalents and Investments (Summary Of Cash, Cash Equivalents And Trading And Available-For-Sale Investments) (Details) - USD ($)
$ in Thousands |
May 31, 2016 |
Nov. 30, 2015 |
| Cash, Cash Equivalents and Investments [Line Items] |
|
|
| Amortized Cost Basis |
$ 229,109
|
$ 241,276
|
| Unrealized Gains |
6
|
30
|
| Unrealized Losses |
(6)
|
(27)
|
| Fair Value |
229,109
|
241,279
|
| State and municipal bond obligations [Member] |
|
|
| Cash, Cash Equivalents and Investments [Line Items] |
|
|
| Amortized Cost Basis |
39,584
|
20,387
|
| Unrealized Gains |
3
|
30
|
| Unrealized Losses |
0
|
0
|
| Fair Value |
39,587
|
20,417
|
| U.S. treasury bonds [Member] |
|
|
| Cash, Cash Equivalents and Investments [Line Items] |
|
|
| Amortized Cost Basis |
4,658
|
3,109
|
| Unrealized Gains |
0
|
0
|
| Unrealized Losses |
(6)
|
(15)
|
| Fair Value |
4,652
|
3,094
|
| U.S. government agency bonds [Member] |
|
|
| Cash, Cash Equivalents and Investments [Line Items] |
|
|
| Amortized Cost Basis |
1,633
|
1,645
|
| Unrealized Gains |
0
|
0
|
| Unrealized Losses |
0
|
(4)
|
| Fair Value |
1,633
|
1,641
|
| Corporate bonds [Member] |
|
|
| Cash, Cash Equivalents and Investments [Line Items] |
|
|
| Amortized Cost Basis |
3,501
|
3,756
|
| Unrealized Gains |
3
|
0
|
| Unrealized Losses |
0
|
(8)
|
| Fair Value |
3,504
|
3,748
|
| Cash [Member] |
|
|
| Cash, Cash Equivalents and Investments [Line Items] |
|
|
| Amortized Cost Basis |
174,198
|
186,241
|
| Unrealized Gains |
0
|
0
|
| Unrealized Losses |
0
|
0
|
| Fair Value |
174,198
|
186,241
|
| Money market funds [Member] |
|
|
| Cash, Cash Equivalents and Investments [Line Items] |
|
|
| Amortized Cost Basis |
5,535
|
26,138
|
| Unrealized Gains |
0
|
0
|
| Unrealized Losses |
0
|
0
|
| Fair Value |
$ 5,535
|
$ 26,138
|