Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Consolidated Statements of Operations [Abstract]
Operating revenue	$ 139,215	$ 119,457	$ 264,152	$ 234,398
Operating expenses:
Labor and benefits	41,859	37,885	83,476	75,636
Equipment rents	8,889	8,637	17,555	17,136
Purchased services	11,327	9,673	20,433	18,228
Diesel fuel	14,578	10,518	28,745	21,762
Casualties and insurance	4,955	4,806	7,089	8,439
Materials	5,928	3,874	11,013	7,799
Joint facilities	2,550	1,945	4,755	4,091
Other expenses	10,672	8,279	20,605	17,377
Track maintenance expense reimbursement	(5,133)		(9,283)
Net (gain) loss on sale of assets	(64)	25	143	(9)
Impairment of assets	3,220		3,220
Depreciation and amortization	11,736	10,755	23,500	21,678
Total operating expenses	110,517	96,397	211,251	192,137
Operating income	28,698	23,060	52,901	42,261
Interest expense (including amortization costs of $4,384, $6,870, $9,242 and $14,174, respectively)	(18,143)	(22,153)	(36,734)	(44,857)
Other income (loss)	495	(7,900)	1,035	(7,441)
Income (loss) from continuing operations before income taxes	11,050	(6,993)	17,202	(10,037)
Provision for (benefit from) income taxes	2,350	(2,772)	4,417	(3,302)
Net income (loss)	$ 8,700	$ (4,221)	$ 12,785	$ (6,735)
Basic earnings (loss) per common share:
Net income (loss)	$ 0.17	$ (0.08)	$ 0.24	$ (0.12)
Diluted earnings (loss) per common share:
Net income (loss)	$ 0.17	$ (0.08)	$ 0.24	$ (0.12)
Weighted Average common shares outstanding:
Basic	52,282	54,869	53,467	54,718
Diluted	52,282	54,869	53,467	54,718