Segment Information (Schedule Of Segment Reporting Information By Segment And Identifiable Assets) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Segment Reporting Information [Line Items]
Total revenues	$ 535,548	$ 470,068	$ 1,017,866	$ 871,004
Cost of services and rentals (exclusive of depreciation, depletion, amortization, and accretion)	369,810	351,802	713,270	673,788
Depreciation, depletion, amortization and accretion	97,973	108,119	203,692	222,400
General and administrative expenses	69,896	76,708	145,716	152,201
Loss from operations	(2,131)	(66,561)	(44,812)	(177,385)
Interest income (expense), net	(24,894)	(23,333)	(49,781)	(47,583)
Other expense	(2,382)	(2,156)	(4,117)	(1,507)
Loss from continuing operations before income taxes	(29,407)	(92,050)	(98,710)	(226,475)
Identifiable Assets	3,020,985		3,020,985		$ 3,110,225
Drilling Products and Services [Member]
Segment Reporting Information [Line Items]
Total revenues	94,033	68,827	179,235	137,258
Cost of services and rentals (exclusive of depreciation, depletion, amortization, and accretion)	36,599	33,002	71,669	62,060
Depreciation, depletion, amortization and accretion	28,590	33,619	58,231	68,348
General and administrative expenses	13,843	12,739	26,367	25,705
Loss from operations	15,001	(10,533)	22,968	(18,855)
Loss from continuing operations before income taxes	15,001	(10,533)	22,968	(18,855)
Identifiable Assets	578,083		578,083		662,968
Onshore Completion and Workover Services [Member]
Segment Reporting Information [Line Items]
Total revenues	276,242	249,079	507,731	454,058
Cost of services and rentals (exclusive of depreciation, depletion, amortization, and accretion)	210,206	207,021	390,857	400,710
Depreciation, depletion, amortization and accretion	47,423	44,621	95,078	93,768
General and administrative expenses	11,102	11,804	24,328	23,075
Loss from operations	7,511	(14,367)	(2,532)	(63,495)
Loss from continuing operations before income taxes	7,511	(14,367)	(2,532)	(63,495)
Identifiable Assets	1,553,343		1,553,343		1,501,214
Production Services [Member]
Segment Reporting Information [Line Items]
Total revenues	102,004	88,606	202,721	157,211
Cost of services and rentals (exclusive of depreciation, depletion, amortization, and accretion)	85,129	71,377	171,065	132,157
Depreciation, depletion, amortization and accretion	14,303	20,193	33,583	40,782
General and administrative expenses	9,696	11,886	19,289	23,167
Loss from operations	(7,124)	(14,850)	(21,216)	(38,895)
Loss from continuing operations before income taxes	(7,124)	(14,850)	(21,216)	(38,895)
Identifiable Assets	491,859		491,859		512,256
Technical Solutions [Member]
Segment Reporting Information [Line Items]
Total revenues	63,269	63,556	128,179	122,477
Cost of services and rentals (exclusive of depreciation, depletion, amortization, and accretion)	37,876	40,402	79,679	78,861
Depreciation, depletion, amortization and accretion	6,273	8,255	14,003	16,631
General and administrative expenses	13,323	13,828	27,383	27,396
Loss from operations	5,797	1,071	7,114	(411)
Interest income (expense), net	971	911	1,927	1,701
Loss from continuing operations before income taxes	6,768	1,982	9,041	1,290
Identifiable Assets	345,196		345,196		377,549
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Depreciation, depletion, amortization and accretion	1,384	1,431	2,797	2,871
General and administrative expenses	21,932	26,451	48,349	52,858
Loss from operations	(23,316)	(27,882)	(51,146)	(55,729)
Interest income (expense), net	(25,865)	(24,244)	(51,708)	(49,284)
Other expense	(2,382)	(2,156)	(4,117)	(1,507)
Loss from continuing operations before income taxes	(51,563)	$ (54,282)	(106,971)	$ (106,520)
Identifiable Assets	$ 52,504		$ 52,504		$ 56,238