Consolidated Statements of Operations (Unaudited) (USD $)	3 Months Ended		9 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Consolidated Statements of Operations [Abstract]
Operating revenues	$ 68,348,000	$ 98,033,000	$ 246,276,000	$ 249,023,000
Operating costs:
Operating expenses	55,652,000	85,431,000	199,668,000	225,324,000
General and administrative	2,570,000	3,804,000	8,046,000	9,396,000
Depreciation	8,328,000	7,900,000	24,092,000	22,767,000
Operating costs, Total	66,550,000	97,135,000	231,806,000	257,487,000
Income (loss) from operations	1,798,000	898,000	14,470,000	(8,464,000)
Other income (expense):
Interest income	5,000	2,000	16,000	33,000
Interest expense	(134,000)		(422,000)
Other income	311,000	21,000	423,000	603,000
Income (loss) before income tax	1,980,000	921,000	14,487,000	(7,828,000)
Income tax (expense) benefit	(839,000)	(587,000)	(4,526,000)	1,638,000
Net income (loss)	$ 1,141,000	$ 334,000	$ 9,961,000	$ (6,190,000)
Basic income (loss) per common share	$ 0.15	$ 0.04	$ 1.27	$ (0.79)
Diluted income (loss) per common share	$ 0.14	$ 0.04	$ 1.26	$ (0.79)
Weighted average equivalent common shares outstanding	7,846,417	7,812,519	7,839,983	7,801,396
Weighted average equivalent common shares outstanding -assuming dilution	7,924,009	7,925,181	7,934,367	7,801,396