Consolidated Statements of Operations (USD $) Share data in Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
OPERATING REVENUES	$ 397,030,000	$ 376,279,000
OPERATING EXPENSES:
Labor and benefits	128,550,000	116,676,000
Equipment rents	20,317,000	19,075,000
Purchased services	19,731,000	27,816,000
Depreciation and amortization	41,813,000	37,641,000
Diesel fuel used in operations	28,051,000	41,935,000
Casualties and insurance	8,369,000	9,633,000
Materials	18,463,000	16,168,000
Trackage rights	12,082,000	12,266,000
Net gain on sale of assets	(317,000)	(838,000)
Other expenses	33,352,000	21,032,000
Freightliner operating expenses	13,999,000	0
Total operating expenses	324,410,000	301,404,000
INCOME FROM OPERATIONS	72,620,000	74,875,000
Interest income	26,000	1,034,000
Interest expense	(13,508,000)	(13,641,000)
Loss on settlement of foreign currency forward purchase contracts	(18,686,000)	0
Other income, net	314,000	636,000
Income before income taxes	40,766,000	62,904,000
Provision for income taxes	(16,862,000)	(22,900,000)
Net income	$ 23,904,000	$ 40,004,000
Basic earnings per common share	$ 0.43	$ 0.73
Weighted average shares - Basic	55,826	54,841
Diluted earnings per common share	$ 0.42	$ 0.70
Weighted average shares - Diluted	57,121	56,905