Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Consolidated Statements of Operations [Abstract]
Operating revenues, net	$ 646,686	$ 539,626	$ 516,935
Expenses:
Direct expenses	543,524	469,740	443,702
Selling, general and administrative expenses	39,051	34,369	30,147
Total operating expenses	582,575	504,109	473,849
Loss (gain) on disposition of assets, net	317	302	(239)
Equity in loss (earnings) of unconsolidated affiliate	863
Operating income	62,931	35,215	43,325
Interest expense	29,533	27,974	19,389
Other (income) expense, net	(651)	(845)	(178)
Loss on debt restructuring			9,521
Total expenses	28,882	27,129	28,732
Earnings before income taxes	34,049	8,086	14,593
Income tax expense	15,992	3,234	7,476
Net earnings	$ 18,057	$ 4,852	$ 7,117
Earnings per share:
Basic	$ 1.17	$ 0.32	$ 0.46
Diluted	$ 1.17	$ 0.31	$ 0.46
Weighted average shares outstanding:
Basic	15,418	15,312	15,312
Diluted	15,488	15,497	15,337