CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS
Net revenues	$ 279,638	$ 262,946	$ 797,155	$ 763,907
Material costs	92,034	84,805	261,810	247,677
Personnel costs	94,594	90,853	272,795	266,515
Other operating costs	32,771	30,999	100,067	92,631
General and administrative expenses	29,834	28,308	87,474	80,467
Professional accounting and legal fees	3,629	3,107	9,576	12,189
Depreciation and amortization	9,373	8,950	26,906	27,552
Income from operations	17,403	15,924	38,527	36,876
Interest expense, net	8,954	8,939	25,973	28,519
Loss on extinguishment of debt				16,998
Non-service defined benefit plan expense	173	176	519	528
Income (loss) before income taxes	8,276	6,809	12,035	(9,169)
Provision (benefit) for income taxes	2,585	2,440	3,260	(3,848)
Net income (loss)	$ 5,691	$ 4,369	$ 8,775	$ (5,321)
Basic and Diluted Per Common Share Data:
Basic income (loss) per share	$ 0.15	$ 0.12	$ 0.24	$ (0.14)
Weighted average shares used to compute basic earnings per common share	37,349,144	36,856,881	37,218,234	36,716,568
Diluted income (loss) per share	$ 0.15	$ 0.12	$ 0.23	$ (0.14)
Weighted average shares used to compute diluted earnings per common share	37,986,860	37,556,594	37,921,767	36,716,568