Reduction in Value of Assets (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Reduction In Value Of Assets And Impairments [Line Items]
Reduction in value of assets	$ 9,953,000	$ 0	$ 9,953,000	$ 462,461,000
Goodwill impairment method weight, discounted cash flow method			80.00%
Goodwill impairment method weight, public company guidline method			20.00%
Reduction in value of goodwill				330,500,000
Goodwill, Impaired, Accumulated Impairment Loss	1,748,200,000		$ 1,748,200,000		$ 1,748,200,000
Reduction in value of long-lived assets			9,900,000	105,859,000
Retirements of long-lived assets				26,102,000
Technical Solutions [Member]
Reduction In Value Of Assets And Impairments [Line Items]
Reduction in value of assets	8,115,000		8,115,000
Production Services [Member]
Reduction In Value Of Assets And Impairments [Line Items]
Reduction in value of assets				226,061,000
Reduction in value of goodwill				190,500,000
Impairment of Property, Plant and Equipment				12,400,000
Impairment of Intangible Assets (Excluding Goodwill)				21,000,000
Onshore Completion and Workover Services [Member]
Reduction In Value Of Assets And Impairments [Line Items]
Reduction in value of assets	$ 1,838,000		$ 1,838,000	188,741,000
Reduction in value of goodwill				140,000,000
Impairment of Property, Plant and Equipment				2,900,000
Impairment of Intangible Assets (Excluding Goodwill)				45,900,000
Drilling Products and Services [Member]
Reduction In Value Of Assets And Impairments [Line Items]
Reduction in value of assets				47,659,000
Impairment of Property, Plant and Equipment				23,700,000
Retirements of long-lived assets				$ 23,900,000