Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents	$ 20,775	$ 68,221
Restricted cash	27,285	2,088
Accounts receivable, net of allowance for doubtful accounts of $6,049 and $5,647, respectively	184,102	206,868
Related party receivables and prepaid expenses	715	711
Inventories, net	15,215	14,314
Prepaid expenses and other current assets	31,799	31,091
Total current assets	279,891	323,293
Property, plant and equipment, net of accumulated depreciation of $196,683 and $193,760, respectively	73,449	87,851
Operating lease right-of-use assets, net	53,937	68,861
Goodwill	358,323	359,781	$ 359,771
Intangible assets, net	244,539	292,664
Deferred income tax assets	2,109	6,606
Other noncurrent assets	24,775	18,723
Total assets	1,037,023	1,157,779
Current liabilities
Accounts payable	61,744	76,027
Related party payables	1,484	97
Income tax payable	3,551	2,466
Accrued liabilities	113,519	126,399
Accrued compensation and benefits	60,860	63,467
Accrued interest	10,075	48,769
Customer deposits	17,707	21,277
Deferred revenue	16,617	16,377
Obligation for claim payment	46,902	29,328
Current portion of finance lease liabilities	6,683	12,231
Current portion of operating lease liabilities	15,923	18,349
Current portion of long-term debts	236,775	39,952
Total current liabilities	591,840	454,739
Long-term debt, net of current maturities	1,012,452	1,498,004
Finance lease liabilities, net of current portion	9,156	13,287
Pension liabilities, net	28,383	35,515
Deferred income tax liabilities	11,594	9,569
Long-term income tax liabilities	3,201	2,759
Operating lease liabilities, net of current portion	41,170	56,814
Other long-term liabilities	5,999	13,624
Total liabilities	1,703,795	2,084,311
Commitments and Contingencies (Note 14)
Stockholders' equity (deficit)
Common stock, par value of $0.0001 per share; 1,600,000,000 shares authorized; 267,646,667 shares issued and 265,194,961 shares outstanding at December 31, 2021	37	15
Preferred stock, par value of $0.0001 per share; 20,000,000 shares authorized; 2,778,111 shares issued and outstanding at December 31, 2021	1	1
Additional paid in capital	838,853	446,739
Less: Common stock held in treasury, at cost; 2,451,706 shares at December 31, 2021	(10,949)	(10,949)
Equity-based compensation	56,123	52,183
Accumulated deficit	(1,532,428)	(1,390,038)
Accumulated other comprehensive loss:
Foreign currency translation adjustment	(7,463)	(7,419)
Unrealized pension actuarial losses, net of tax	(10,946)	(17,064)
Total accumulated other comprehensive loss	(18,409)	(24,483)
Total stockholders' deficit	(666,772)	(926,532)	$ (743,040)	$ (241,259)
Total liabilities and stockholders' deficit	$ 1,037,023	$ 1,157,779