| 
           Employee Benefits Plans (Schedule of MSP Benefit Expense) (Details) (USD $) 
        In Thousands, unless otherwise specified  | 
        12 Months Ended | ||
|---|---|---|---|
| 
           Sep. 30, 2013 
         | 
        
           Sep. 30, 2012 
         | 
        
           Sep. 30, 2011 
         | 
      |
| MSP benefit expense charged to costs and expenses: | |||
| Service cost | $ 221 | $ 251 | $ 233 | 
| Interest cost | 368 | 178 | 181 | 
| Recognized actuarial loss adjustment | 2 | 66 | |
| Total | $ 589 | $ 431 | $ 480 | 
| X | ||||||||||
| 
             
- Definition 
          The amount of gains or losses recognized in net periodic benefit cost. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
  | 
        
| X | ||||||||||
| 
             
- Definition 
          The increase in a defined benefit pension plan's projected benefit obligation or a defined benefit postretirement plan's accumulated postretirement benefit obligation due to the passage of time. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
  | 
        
| X | ||||||||||
| 
             
- Definition 
          The total amount of net periodic benefit cost for defined benefit plans for the period. Periodic benefit costs include the following components: service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) due to settlements or curtailments. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
  | 
        
| X | ||||||||||
| 
             
- Details 
          
  | 
        
| X | ||||||||||
| 
             
- Definition 
          The actuarial present value of benefits attributed by the pension benefit formula to services rendered by employees during the period. The portion of the expected postretirement benefit obligation attributed to employee service during the period. The service cost component is a portion of the benefit obligation and is unaffected by the funded status of the plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
  |