Consolidated Statements of Operations (Unaudited) (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
Consolidated Statements of Operations [Abstract]
Revenue	$ 183,110	$ 180,074	$ 393,001	$ 389,455
Operating expenses	159,931	158,260	329,359	329,709
Gross margin	23,179	21,814	63,642	59,746
Corporate general and administrative expenses	6,850	6,638	16,511	15,622
Operating income	16,329	15,176	47,131	44,124
Other income (expense):
Interest expense	(4,407)	(3,411)	(9,322)	(6,579)
Gain on sale of operations, net	2	2	2,745	376
Other income (expense), net	27	(2,047)	3,108	126
Total other expense, net	(4,378)	(5,456)	(3,469)	(6,077)
Income from continuing operations before income tax expense	11,951	9,720	43,662	38,047
Income tax expense	5,095	2,711	18,682	14,182
Income from continuing operations after income tax expense	6,856	7,009	24,980	23,865
Loss from discontinued operations, net of tax	(335)	(991)	(594)	(1,427)
Gain (loss) on disposal of discontinued operations, net of tax	30	(596)	70	(1,032)
Net income	$ 6,551	$ 5,422	$ 24,456	$ 21,406
Basic:
Continuing operations	$ 0.14	$ 0.11	$ 0.50	$ 0.39
Discontinued operations	$ (0.01)	$ (0.02)	$ (0.01)	$ (0.04)
Net income	$ 0.13	$ 0.09	$ 0.49	$ 0.35
Diluted:
Continuing operations	$ 0.14	$ 0.11	$ 0.50	$ 0.39
Discontinued operations	$ (0.01)	$ (0.02)	$ (0.01)	$ (0.04)
Net income	$ 0.13	$ 0.09	$ 0.49	$ 0.35
Basic weighted average shares outstanding	49,615	61,448	49,469	61,479
Diluted weighted average shares outstanding	49,958	61,837	49,880	61,972