| Schedule of Quarterly Financial Data | 
        
 
  Summarized quarterly financial data (in thousands except for per share amounts) for the fiscal years ended September 30, 2013 and 2012 were as follows:  
|  (in thousands) |  Fiscal Quarter Ended |   
|   |  December 31, |     |  March 31, |     |  June 30, |     |  September 30, |   
|   |  2012 |     |  2011 |     |  2013 |     |  2012 |     |  2013 |     |  2012 |     |  2013 |     |  2012 |   
|   |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |   
|   Total operating revenue |   $ |   21,356 |     |     |   $ |   26,047 |     |     |   $ |   38,410 |     |     |   $ |   54,097 |     |     |   $ |   35,229 |     |     |   $ |   40,401 |     |     |   $ |   6,666 |     |     |   $ |   6,642 |     |   
|   Total operating expenses |     |   17,570 |     |     |     |   20,533 |     |     |     |   31,396 |     |     |     |   39,859 |     |     |     |   26,164 |     |     |     |   29,892 |     |     |     |   4,857 |     |     |     |   4,671 |     |   
|   |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |   
|   Gross profit |     |   3,786 |     |     |     |   5,514 |     |     |     |   7,014 |     |     |     |   14,238 |     |     |     |   9,065 |     |     |     |   10,509 |     |     |     |   1,809 |     |     |     |   1,971 |     |   
|   Corporate, general and |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |   
|   administrative |     |   1,808 |     |     |     |   1,990 |     |     |     |   2,464 |     |     |     |   1,807 |     |     |     |   2,253 |     |     |     |   1,871 |     |     |     |   3,214 |     |     |     |   2,822 |     |   
|   Other (expense) income |     |   (304 |   ) |     |     |   (360 |   ) |     |     |   23 |     |     |     |   (502 |   ) |     |     |   (167 |   ) |     |     |   6,888 |     |     |     |   20,188 |     |     |     |   (306 |   ) |   
|   |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |   
|   Income (loss) before income taxes |     |   1,674 |     |     |     |   3,164 |     |     |     |   4,573 |     |     |     |   11,929 |     |     |     |   6,645 |     |     |     |   15,526 |     |     |     |   18,783 |     |     |     |   (1,157 |   ) |   
|   Income tax expense (benefit) |     |   636 |     |     |     |   1,231 |     |     |     |   1,800 |     |     |     |   4,515 |     |     |     |   2,566 |     |     |     |   5,919 |     |     |     |   7,027 |     |     |     |   (692 |   ) |   
|   |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |   
|   Net (loss) income |   $ |   1,038 |     |     |   $ |   1,933 |     |     |   $ |   2,773 |     |     |   $ |   7,414 |     |     |   $ |   4,079 |     |     |   $ |   9,607 |     |     |   $ |   11,756 |     |     |   $ |   (465 |   ) |   
|   |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |   
|   Earnings per share: |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |   
|   Basic |   $ |   0.14 |     |     |   $ |   0.26 |     |     |   $ |   0.38 |     |     |   $ |   1.01 |     |     |   $ |   0.56 |     |     |   $ |   1.31 |     |     |   $ |   1.61 |     |     |   $ |   (0.07 |   ) |   
|   Diluted |   $ |   0.14 |     |     |   $ |   0.26 |     |     |   $ |   0.38 |     |     |   $ |   1.01 |     |     |   $ |   0.55 |     |     |   $ |   1.31 |     |     |   $ |   1.60 |     |     |   $ |   (0.07 |   ) |   
 
   
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