Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Revenue	$ 187,102	$ 180,269	$ 586,010	$ 562,461
Operating expenses	159,175	155,233	493,156	475,488
Gross margin	27,927	25,036	92,854	86,973
Corporate general and administrative expenses	8,043	8,889	24,523	27,393
Operating income	19,884	16,147	68,331	59,580
Other (expense) income:
Interest expense	(1,840)	(3,123)	(7,665)	(10,133)
Gain on sale of operations, net	5	17	106	93
Other (expense) income, net	(1,673)	(1,368)	60	4,543
Total other expense, net	(3,508)	(4,474)	(7,499)	(5,497)
Income from continuing operations before income tax expense	16,376	11,673	60,832	54,083
Income tax expense	6,787	4,353	25,055	22,291
Income from continuing operations	9,589	7,320	35,777	31,792
Loss from discontinued operations, net of tax	(561)	(239)	(1,226)	(814)
Gain on disposal of discontinued operations, net of tax	1,172	607	1,462	106
Net income	$ 10,200	$ 7,688	$ 36,013	$ 31,084
Basic:
Continuing operations	$ 0.19	$ 0.15	$ 0.72	$ 0.66
Discontinued operations	0.01	0.01		(0.02)
Net income	0.20	0.16	0.72	0.64
Diluted:
Continuing operations	0.18	0.14	0.68	0.62
Discontinued operations	0.01	0.01	0.01	(0.02)
Net income	$ 0.19	$ 0.15	$ 0.69	$ 0.60
Basic weighted average shares outstanding	51,736	48,451	49,812	48,303
Diluted weighted average shares outstanding	54,445	51,209	52,285	51,469
Comprehensive Income:
Net income	$ 10,200	$ 7,688	$ 36,013	$ 31,084
Other comprehensive income (loss), net of tax	16	(66)	62	31
Comprehensive income	$ 10,216	$ 7,622	$ 36,075	$ 31,115