Consolidated Statements Of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues:
Revenues	$ 1,425,369	$ 1,478,857	$ 1,305,529
Costs and expenses:
Cost or revenues (exclusive of depreciation, depletion, amortization and accretion)	925,082	970,488	889,809
Depreciation, depletion, amortization and accretion	196,459	278,439	326,856
General and administrative expenses	268,226	276,468	285,597
Reduction in value of assets	17,185	322,713	10,390
Income (loss) from operations	18,417	(369,251)	(207,123)
Other expense:
Interest expense, net	(98,312)	(99,477)	(101,455)
Other expense	(2,484)	(1,678)	(3,299)
Loss from continuing operations before income taxes	(82,379)	(470,406)	(311,877)
Income taxes	(4,626)	(43,003)	(131,562)
Net loss from continuing operations	(77,753)	(427,403)	(180,315)
Loss from discontinued operations, net of income tax	(177,968)	(430,712)	(25,606)
Net loss	$ (255,721)	$ (858,115)	$ (205,921)
Basic and diluted loss per share:
Net loss from continuing operations	$ (5.05)	$ (27.69)	$ (11.79)
Loss from discontinued operations	(11.56)	(27.90)	(1.68)
Net loss	$ (16.61)	$ (55.59)	$ (13.47)
Weighted average shares outstanding	15,393	15,437	15,293
Services [Member]
Revenues:
Revenues	$ 885,252	$ 933,029	$ 868,211
Costs and expenses:
Cost or revenues (exclusive of depreciation, depletion, amortization and accretion)	698,150	699,322	675,896
Depreciation, depletion, amortization and accretion	121,805	175,417	218,994
Rentals [Member]
Revenues:
Revenues	376,247	380,296	279,936
Costs and expenses:
Cost or revenues (exclusive of depreciation, depletion, amortization and accretion)	128,695	136,135	114,128
Depreciation, depletion, amortization and accretion	59,189	71,661	65,929
Product Sales [Member]
Revenues:
Revenues	163,870	165,532	157,382
Costs and expenses:
Cost or revenues (exclusive of depreciation, depletion, amortization and accretion)	98,237	135,031	99,785
Depreciation, depletion, amortization and accretion	$ 15,465	$ 31,361	$ 41,933