Consolidated Statements of Operations (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
OPERATING REVENUES	$ 209,589	$ 158,453	$ 401,500	$ 304,032
OPERATING EXPENSES:
Labor and benefits	58,966	51,329	117,048	101,517
Equipment rents	11,011	8,266	21,578	15,915
Purchased services	19,942	12,895	37,384	23,292
Depreciation and amortization	16,297	12,452	32,158	24,900
Diesel fuel used in operations	22,629	10,605	44,027	21,642
Diesel fuel sold to third parties	4,500	3,910	8,579	7,703
Casualties and insurance	6,228	3,123	11,666	7,027
Materials	6,090	6,004	12,673	11,481
Net gain on sale of assets	(1,088)	(1,399)	(2,098)	(1,848)
Gain on insurance recoveries	(1,018)	0	(1,043)	0
Other operating expenses	14,867	13,395	29,160	24,424
Total operating expenses	158,424	120,580	311,132	236,053
INCOME FROM OPERATIONS	51,165	37,873	90,368	67,979
Interest income	858	471	1,633	894
Interest expense	(10,253)	(5,411)	(20,192)	(10,773)
Gain on sale of investments	625	0	894	0
Other income/(expense), net	170	(175)	469	275
Income from continuing operations before income taxes	42,565	32,758	73,172	58,375
Provision for income taxes	11,420	12,067	19,905	21,708
Income from continuing operations, net of tax	31,145	20,691	53,267	36,667
Loss from discontinued operations, net of tax	0	(56)	0	(72)
Net income	$ 31,145	$ 20,635	$ 53,267	$ 36,595
Basic earnings per share:
Basic earnings per common share from continuing operations	$ 0.78	$ 0.53	$ 1.34	$ 0.95
Basic loss per common share from discontinued operations	$ 0.00	$ 0.00	$ 0.00	$ 0.00
Basic earnings per common share	$ 0.78	$ 0.53	$ 1.34	$ 0.95
Weighted average shares - basic	39,903	38,831	39,695	38,711
Diluted earnings per share:
Diluted earnings per common share from continuing operations	$ 0.73	$ 0.50	$ 1.25	$ 0.88
Diluted loss per common share from discontinued operations	$ 0.00	$ 0.00	$ 0.00	$ 0.00
Diluted earnings per common share	$ 0.73	$ 0.49	$ 1.25	$ 0.88
Weighted average shares - diluted	42,757	41,723	42,654	41,595