Employee Benefit Plans (Schedule of Actual and Expected Employer Contributions) (Details) |
9 Months Ended |
|---|---|
|
Jun. 30, 2017
USD ($)
| |
| Defined Benefit Plan Disclosure [Line Items] | |
| Fiscal Year-to-Date Contributions | $ 450,000 |
| Fiscal Year-to-Date Expected Future Employer Contributions | 1,300,000 |
| Defined Benefit Pension Plan [Member] | |
| Defined Benefit Plan Disclosure [Line Items] | |
| Fiscal Year-to-Date Contributions | 450,000 |
| Fiscal Year-to-Date Expected Future Employer Contributions | 300,000 |
| Postretirement Medical Plan [Member] | |
| Defined Benefit Plan Disclosure [Line Items] | |
| Fiscal Year-to-Date Contributions | 0 |
| Fiscal Year-to-Date Expected Future Employer Contributions | $ 1,000,000 |