Fair Value Measurements - Fair Value Measurements (Details) - Fair Value, Recurring [Member] - USD ($)
$ in Thousands |
May 31, 2021 |
Aug. 31, 2020 |
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Deferred compensation assets |
$ 50,660
|
$ 47,669
|
| Embedded derivative asset |
16,173
|
18,998
|
| Securities Segregated under Other Regulations |
195,197
|
85,950
|
| Other assets |
6,563
|
5,276
|
| Total assets |
1,152,896
|
530,961
|
| Foreign exchange derivatives |
|
69,467
|
| Total liabilities |
602,326
|
421,630
|
| Quoted Prices in Active Markets for Identical Assets (Level 1) |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Deferred compensation assets |
50,660
|
47,669
|
| Embedded derivative asset |
0
|
0
|
| Securities Segregated under Other Regulations |
195,197
|
85,950
|
| Other assets |
6,563
|
5,276
|
| Total assets |
254,769
|
144,657
|
| Foreign exchange derivatives |
|
0
|
| Total liabilities |
1,037
|
6,037
|
| Significant Other Observable Inputs (Level 2) |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Deferred compensation assets |
0
|
0
|
| Embedded derivative asset |
16,173
|
18,998
|
| Securities Segregated under Other Regulations |
0
|
0
|
| Other assets |
0
|
0
|
| Total assets |
898,127
|
386,304
|
| Foreign exchange derivatives |
|
69,467
|
| Total liabilities |
601,289
|
415,593
|
| Fair Value, Inputs, Level 3 [Member] |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Deferred compensation assets |
0
|
0
|
| Embedded derivative asset |
0
|
0
|
| Securities Segregated under Other Regulations |
0
|
0
|
| Other assets |
0
|
0
|
| Total assets |
0
|
0
|
| Foreign exchange derivatives |
|
0
|
| Total liabilities |
0
|
0
|
| Commodity derivatives |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Derivative Asset |
854,971
|
361,545
|
| Derivative Liability |
592,419
|
352,163
|
| Commodity derivatives | Quoted Prices in Active Markets for Identical Assets (Level 1) |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Derivative Asset |
2,349
|
5,762
|
| Derivative Liability |
1,037
|
6,037
|
| Commodity derivatives | Significant Other Observable Inputs (Level 2) |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Derivative Asset |
852,622
|
355,783
|
| Derivative Liability |
591,382
|
346,126
|
| Commodity derivatives | Fair Value, Inputs, Level 3 [Member] |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Derivative Asset |
0
|
0
|
| Derivative Liability |
0
|
0
|
| Foreign exchange derivatives |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Foreign exchange derivatives |
29,332
|
11,523
|
| Foreign exchange derivatives |
9,907
|
|
| Foreign exchange derivatives | Quoted Prices in Active Markets for Identical Assets (Level 1) |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Foreign exchange derivatives |
0
|
0
|
| Foreign exchange derivatives |
0
|
|
| Foreign exchange derivatives | Significant Other Observable Inputs (Level 2) |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Foreign exchange derivatives |
29,332
|
11,523
|
| Foreign exchange derivatives |
9,907
|
|
| Foreign exchange derivatives | Fair Value, Inputs, Level 3 [Member] |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Foreign exchange derivatives |
0
|
$ 0
|
| Foreign exchange derivatives |
$ 0
|
|