CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Revenues	$ 151,133	$ 146,185	$ 421,236	$ 406,476
Operating expenses:
Cost of operations	98,803	99,656	284,409	286,225
General and administration	18,777	17,448	55,450	52,324
Depreciation and amortization	16,175	16,385	46,430	46,374
Divestiture transactions	0	0	0	(5,611)
Total operating expenses	133,755	133,489	386,289	379,312
Operating income	17,378	12,696	34,947	27,164
Other expense (income):
Interest income	(64)	(56)	(229)	(267)
Interest expense	9,643	10,087	29,677	30,363
Loss on debt extinguishment	191	345	736	866
Loss on derivative instruments	0	41	0	239
Other income	(192)	(178)	(697)	(387)
Other expense, net	9,578	10,239	29,487	30,814
Income (loss) before income taxes	7,800	2,457	5,460	(3,650)
Provision for income taxes	263	198	344	1,112
Net income (loss)	7,537	2,259	5,116	(4,762)
Less: Net income (loss) attributable to noncontrolling interests	0	(37)	(9)	1,189
Net income (loss) attributable to common stockholders	$ 7,537	$ 2,296	$ 5,125	$ (5,951)
Basic earnings per share attributable to common stockholders:
Basic weighted average common shares outstanding (in shares)	41,377	40,810	41,169	40,560
Basic earnings per share (in USD per share)	$ 0.18	$ 0.06	$ 0.12	$ (0.15)
Diluted earnings per share attributable to common stockholders:
Diluted weighted average common shares outstanding (in shares)	42,287	41,283	41,896	40,560
Diluted earnings per share (in USD per share)	$ 0.18	$ 0.06	$ 0.12	$ (0.15)