Acquisitions (Identifiable Intangible Assets Acquired) (Details) - USD ($) $ in Thousands	Nov. 23, 2015	Mar. 13, 2015	Jan. 13, 2015
TEW Plus LTD [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets	$ 1,074
TEW Plus LTD [Member] | Trade name [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets	0
TEW Plus LTD [Member] | Customer relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets	817
TEW Plus LTD [Member] | Technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets	203
TEW Plus LTD [Member] | Non-compete agreements [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets	$ 54
Inspection Oilfield Services (IOS) [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets		$ 50,354
Inspection Oilfield Services (IOS) [Member] | Trade name [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets		2,641
Inspection Oilfield Services (IOS) [Member] | Customer relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets		41,171
Inspection Oilfield Services (IOS) [Member] | Technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets		4,364
Inspection Oilfield Services (IOS) [Member] | Non-compete agreements [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets		$ 2,178
TEW Holdings, LTD [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets			$ 14,048
TEW Holdings, LTD [Member] | Trade name [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets			870
TEW Holdings, LTD [Member] | Customer relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets			10,035
TEW Holdings, LTD [Member] | Technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets			2,480
TEW Holdings, LTD [Member] | Non-compete agreements [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value estimate of acquired identifiable intangible assets			$ 663