Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Consolidated Statements of Operations [Abstract]
Operating revenue	$ 143,442	$ 124,937
Operating expenses:
Labor and benefits	45,552	41,617
Equipment rents	8,396	8,666
Purchased services	10,970	9,106
Diesel fuel	13,425	14,167
Casualties and insurance	2,879	2,134
Materials	6,409	5,085
Joint facilities	2,591	2,205
Other expenses	11,101	9,933
Track maintenance expense reimbursement		(4,150)
Net (gain) loss on sale of assets	(163)	207
Depreciation and amortization	10,406	11,764
Total operating expenses	111,566	100,734
Operating income	31,876	24,203
Interest expense (including amortization costs of $2,616 and $4,858, respectively)	(13,411)	(18,591)
Other (loss) income	(81,942)	540
(Loss) income before income taxes	(63,477)	6,152
(Benefit from) provision for income taxes	(23,258)	2,067
Net (loss) income	$ (40,219)	$ 4,085
Basic earnings per common share:
Net (loss) income	$ (0.80)	$ 0.07
Diluted earnings per common share:
Net (loss) income	$ (0.80)	$ 0.07
Weighted Average common shares outstanding:
Basic	50,518	54,651
Diluted	50,518	54,651