Employee Benefit Plans (Schedule of Components of Net Periodic Pension and Postretirement Benefit Cost) (Details) - USD ($) |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2017 |
Jun. 30, 2016 |
Jun. 30, 2017 |
Jun. 30, 2016 |
|
| Pension Plan [Member] | ||||
| Defined Benefit Plan Disclosure [Line Items] | ||||
| Service cost | $ 176,669 | $ 173,594 | $ 530,007 | $ 520,782 |
| Interest cost | 248,900 | 283,194 | 746,700 | 849,582 |
| Expected return on plan assets | (404,103) | (373,060) | (1,212,309) | (1,119,180) |
| Recognized loss | 165,545 | 125,420 | 496,635 | 376,260 |
| Net periodic/postretirement pension/benefit cost | 187,011 | 209,148 | 561,033 | 627,444 |
| Postretirement Plan [Member] | ||||
| Defined Benefit Plan Disclosure [Line Items] | ||||
| Service cost | 45,817 | 37,005 | 137,451 | 111,015 |
| Interest cost | 156,706 | 156,145 | 470,118 | 468,435 |
| Expected return on plan assets | (142,878) | (126,965) | (428,634) | (380,895) |
| Recognized loss | 107,440 | 62,543 | 322,320 | 187,629 |
| Net periodic/postretirement pension/benefit cost | $ 167,085 | $ 128,728 | $ 501,255 | $ 386,184 |