CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Statement [Abstract]
Revenues		$ 135,397	$ 248,115	$ 283,951	$ 480,051
Costs and expenses:
Cost of operations		102,907	203,831	217,535	404,898
Selling, general and administrative expenses		34,579	42,076	72,187	84,475
Advisory fees and settlement costs		1,989	4,778	6,228	18,388
Restructuring activities		2,392	936	4,343	7,015
Research and development costs		1,231	710	2,572	1,453
Loss (gain) on asset disposals, net		2	42	(913)	42
Total costs and expenses		143,100	252,373	301,952	516,271
Operating loss		(7,703)	(4,258)	(18,001)	(36,220)
Other (expense) income:
Interest expense		(15,482)	(26,837)	(37,573)	(37,971)
Interest income		223	201	263	760
Loss on debt extinguishment		(6,194)	(3,969)	(6,194)	(3,969)
Loss on sale of business		(108)	(3,601)	(108)	(3,601)
Benefit plans, net		7,450	2,471	14,986	5,501
Foreign exchange		7,112	9,506	(2,214)	(647)
Other – net		(2,586)	43	(2,792)	463
Total other expense		(9,585)	(22,186)	(33,632)	(39,464)
Loss before income tax (benefit) expense		(17,288)	(26,444)	(51,633)	(75,684)
Income tax expense		845	1,891	35	2,517
Loss from continuing operations		(18,133)	(28,335)	(51,668)	(78,201)
(Loss) income from discontinued operations, net of tax		(113)	694	1,800	694
Net loss		(18,246)	(27,641)	(49,868)	(77,507)
Net income attributable to non-controlling interest		142	1	238	102
Net loss attributable to stockholders		$ (18,104)	$ (27,640)	$ (49,630)	$ (77,405)
Basic and diluted loss per share - continuing operations (in dollars per share)		$ (0.39)	$ (1.54)	$ (1.10)	$ (4.26)
Basic and diluted earnings per share - discontinued operations (in dollars per share)		0.00	0.04	0.04	0.04
Basic and diluted loss per share (in dollars per share)		$ (0.39)	$ (1.50)	$ (1.06)	$ (4.22)
Shares used in the computation of (loss) earnings per share:
Basic and diluted (in shares)	[1]	46,853	18,366	46,628	18,362

[1] Basic and diluted shares at June 30, 2019 reflect the bonus element for the 2019 Rights Offering on July 23, 2019 and the one-for-ten reverse stock split on July 24, 2019.