Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Statement [Abstract]
Revenues	$ 144,670	$ 143,714	$ 270,103	$ 260,292
Operating expenses:
Cost of operations	95,188	98,737	185,606	186,569
General and administration	18,084	18,071	36,672	34,876
Depreciation and amortization	15,802	16,241	30,255	29,990
Divestiture transactions		(677)		(5,611)
Total operating expenses	129,074	132,372	252,533	245,824
Operating income	15,596	11,342	17,570	14,468
Other expense (income):
Interest income	(60)	(70)	(164)	(211)
Interest expense	10,004	10,150	20,034	20,276
Loss on debt extinguishment	593		545	521
Loss on derivative instruments		47		198
Other income	(363)	(46)	(504)	(209)
Other expense, net	10,174	10,081	19,911	20,575
Income (loss) before income taxes	5,422	1,261	(2,341)	(6,107)
Provision for income taxes	230	318	81	914
Net income (loss)	5,192	943	(2,422)	(7,021)
Less: Net (loss) income attributable to noncontrolling interests	(3)	(82)	(9)	1,226
Net income (loss) attributable to common stockholders	$ 5,195	$ 1,025	$ (2,413)	$ (8,247)
Basic earnings per share attributable to common stockholders:
Weighted average common shares outstanding	41,132	40,447	41,064	40,432
Basic earnings per share	$ 0.13	$ 0.03	$ (0.06)	$ (0.20)
Diluted earnings per share attributable to common stockholders:
Weighted average common shares outstanding	41,598	40,846	41,064	40,432
Diluted earnings per share	$ 0.12	$ 0.03	$ (0.06)	$ (0.20)