Guarantor/Non Guarantor Condensed Consolidating Financial Statements (Balance Sheet)) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 28,081	$ 24,619
Restricted cash	4,021	998
Receivables, net of allowance	56,353	123,526
Intercompany receivable (payable)	0	0
Inventory	13,297	22,453
Assets held for sale	4,295	3,447
Prepaid expenses and other current assets	4,341	7,869
Total current assets	110,388	182,912
Net property and equipment	172,397	471,170
Investments in subsidiaries	0	0
Intangible assets, net of accumulated amortization	9,058	0
Deferred income taxes	10,433	11,540
Operating lease assets	4,664	7,264
Other noncurrent assets	12,162	1,068
Total assets	319,102	673,954
Current liabilities:
Accounts payable	15,445	32,551
Current portion of long-term debt	2,199	0
Deferred revenues	715	1,339
Accrued expenses	40,603	57,691
Total current liabilities	58,962	91,581
Long-term debt, less unamortized discount and debt issuance costs	143,017	467,699
Noncurrent operating lease liabilities	3,838	5,700
Deferred income taxes	903	4,417
Other noncurrent liabilities	2,337	481
Total liabilities	209,057	569,878
Total shareholders' equity	110,045	104,076
Total liabilities and stockholders' equity	319,102	673,954
Eliminations [Member]
Current assets:
Cash and cash equivalents	0	0
Restricted cash	0	0
Receivables, net of allowance	0	117
Intercompany receivable (payable)	0	0
Inventory	0	0
Assets held for sale	0	0
Prepaid expenses and other current assets	0	0
Total current assets	0	117
Net property and equipment	0	0
Investments in subsidiaries	(269,296)	(595,076)
Intangible assets, net of accumulated amortization	0
Deferred income taxes	0	(44,224)
Operating lease assets	0	0
Other noncurrent assets	0	0
Total assets	(269,296)	(639,183)
Current liabilities:
Accounts payable	0	0
Current portion of long-term debt	0
Deferred revenues	0	0
Accrued expenses	0	117
Total current liabilities	0	117
Long-term debt, less unamortized discount and debt issuance costs	0	0
Noncurrent operating lease liabilities	0	0
Deferred income taxes	0	(44,224)
Other noncurrent liabilities	0	0
Total liabilities	0	(44,107)
Total shareholders' equity	(269,296)	(595,076)
Total liabilities and stockholders' equity	(269,296)	(639,183)
Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	0	0
Restricted cash	0	0
Receivables, net of allowance	46,252	92,394
Intercompany receivable (payable)	31,141	64,485
Inventory	5,636	10,325
Assets held for sale	4,295	3,447
Prepaid expenses and other current assets	1,319	4,122
Total current assets	88,643	174,773
Net property and equipment	149,982	441,567
Investments in subsidiaries	33,817	47,953
Intangible assets, net of accumulated amortization	7,156
Deferred income taxes	0	0
Operating lease assets	1,977	3,581
Other noncurrent assets	52	562
Total assets	281,627	668,436
Current liabilities:
Accounts payable	8,608	24,436
Current portion of long-term debt	0
Deferred revenues	205	513
Accrued expenses	33,019	44,893
Total current liabilities	41,832	69,842
Long-term debt, less unamortized discount and debt issuance costs	0	0
Noncurrent operating lease liabilities	1,489	2,536
Deferred income taxes	732	48,641
Other noncurrent liabilities	2,095	294
Total liabilities	46,148	121,313
Total shareholders' equity	235,479	547,123
Total liabilities and stockholders' equity	281,627	668,436
Non-Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	5,465	10,158
Restricted cash	0	0
Receivables, net of allowance	8,991	30,908
Intercompany receivable (payable)	(28,010)	(35,821)
Inventory	7,661	12,128
Assets held for sale	0	0
Prepaid expenses and other current assets	657	898
Total current assets	(5,236)	18,271
Net property and equipment	22,013	27,229
Investments in subsidiaries	0	0
Intangible assets, net of accumulated amortization	0
Deferred income taxes	10,433	11,540
Operating lease assets	0	569
Other noncurrent assets	9,898	0
Total assets	37,108	57,609
Current liabilities:
Accounts payable	2,112	6,304
Current portion of long-term debt	0
Deferred revenues	510	826
Accrued expenses	669	2,111
Total current liabilities	3,291	9,241
Long-term debt, less unamortized discount and debt issuance costs	0	0
Noncurrent operating lease liabilities	0	415
Deferred income taxes	0	0
Other noncurrent liabilities	0	0
Total liabilities	3,291	9,656
Total shareholders' equity	33,817	47,953
Total liabilities and stockholders' equity	37,108	57,609
Parent [Member]
Current assets:
Cash and cash equivalents	22,616	14,461
Restricted cash	4,021	998
Receivables, net of allowance	1,110	107
Intercompany receivable (payable)	(3,131)	(28,664)
Inventory	0	0
Assets held for sale	0	0
Prepaid expenses and other current assets	2,365	2,849
Total current assets	26,981	(10,249)
Net property and equipment	402	2,374
Investments in subsidiaries	235,479	547,123
Intangible assets, net of accumulated amortization	1,902
Deferred income taxes	0	44,224
Operating lease assets	2,687	3,114
Other noncurrent assets	2,212	506
Total assets	269,663	587,092
Current liabilities:
Accounts payable	4,725	1,811
Current portion of long-term debt	2,199
Deferred revenues	0	0
Accrued expenses	6,915	10,570
Total current liabilities	13,839	12,381
Long-term debt, less unamortized discount and debt issuance costs	143,017	467,699
Noncurrent operating lease liabilities	2,349	2,749
Deferred income taxes	171	0
Other noncurrent liabilities	242	187
Total liabilities	159,618	483,016
Total shareholders' equity	110,045	104,076
Total liabilities and stockholders' equity	$ 269,663	$ 587,092