Consolidated Statements of Operations (USD $) In Thousands, except Per Share data	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
OPERATING REVENUES	$ 217,210	$ 156,492	$ 618,710	$ 460,524
OPERATING EXPENSES:
Labor and benefits	58,986	50,840	176,034	152,357
Equipment rents	11,383	8,201	32,961	24,116
Purchased services	20,349	13,965	57,733	37,257
Depreciation and amortization	16,623	12,506	48,781	37,406
Diesel fuel used in operations	21,415	10,037	65,442	31,679
Diesel fuel sold to third parties	3,662	4,840	12,241	12,543
Casualties and insurance	5,020	3,104	16,686	10,131
Materials	6,844	5,349	19,517	16,830
Net gain on sale of assets	(610)	(2,434)	(2,708)	(4,282)
Gain on insurance recoveries	0	0	(1,043)	0
Restructuring charges	0	(2,349)	0	(2,349)
Other operating expenses	17,515	13,921	46,675	38,345
Total operating expenses	161,187	117,980	472,319	354,033
INCOME FROM OPERATIONS	56,023	38,512	146,391	106,491
Interest income	853	703	2,486	1,597
Interest expense	(10,573)	(5,474)	(30,765)	(16,247)
Gain on sale of investments	0	0	894	0
Other (expense)/income, net	(1,064)	418	(595)	693
Income from continuing operations before income taxes	45,239	34,159	118,411	92,534
Provision for income taxes	12,287	12,109	32,192	33,817
Income from continuing operations, net of tax	32,952	22,050	86,219	58,717
(Loss)/income from discontinued operations, net of tax	(10)	2,745	(10)	2,673
Net income	$ 32,942	$ 24,795	$ 86,209	$ 61,390
Basic earnings per share:
Basic earnings per common share from continuing operations	$ 0.82	$ 0.57	$ 2.16	$ 1.51
Basic (loss)/income per common share from discontinued operations	$ 0.00	$ 0.07	$ 0.00	$ 0.07
Basic earnings per common share	$ 0.82	$ 0.64	$ 2.16	$ 1.58
Weighted average shares - basic	40,078	38,940	39,825	38,774
Diluted earnings per share:
Diluted earnings per common share from continuing operations	$ 0.77	$ 0.53	$ 2.02	$ 1.41
Diluted (loss)/income per common share from discontinued operations	$ 0.00	$ 0.07	$ 0.00	$ 0.06
Diluted earnings per common share	$ 0.77	$ 0.59	$ 2.02	$ 1.47
Weighted average shares - diluted	42,821	41,894	42,711	41,675