CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Revenue from services	$ 836,417	$ 822,224	$ 816,484
Operating expenses:
Direct operating expenses	633,685	618,215	606,921
Selling, general and administrative expenses	173,809	181,959	180,230
Bad debt expense	3,035	2,008	2,204
Depreciation and amortization	12,671	14,075	11,780
Acquisition and integration-related costs	77	201	3,048
Restructuring costs	6,052	3,571	2,758
Legal settlement charges	0	1,600	0
Impairment charges	16,248	16,306	22,423
Total operating expenses	845,577	837,935	829,364
Loss from operations	(9,160)	(15,711)	(12,880)
Other expenses (income):
Interest expense	2,890	5,306	5,654
Loss on derivative	0	1,284	0
Loss on early extinguishment of debt	0	1,978	79
Other expense (income), net	280	(68)	(418)
Loss before income taxes	(12,330)	(24,211)	(18,195)
Income tax (benefit) expense	(188)	31,732	(2,478)
Consolidated net loss	(12,142)	(55,943)	(15,717)
Less: Net income attributable to noncontrolling interest in subsidiary	820	1,770	1,234
Net loss attributable to common shareholders	$ (12,962)	$ (57,713)	$ (16,951)
Net (loss) income per share attributable to common shareholders - Basic and diluted (usd per share)	$ (0.36)	$ (1.61)	$ (0.48)
Weighted average common shares outstanding—basic and diluted (shares)	36,088	35,815	35,657
Revenue from Contract with Customer, Product and Service [Extensible List]	us-gaap:ServiceMember	us-gaap:ServiceMember	us-gaap:ServiceMember