Acquisitions (Details) (USD $)	12 Months Ended		1 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Jan. 31, 2013	Oct. 31, 2013 item	Oct. 31, 2014	Dec. 31, 2012
Business Acquisition [Line Items]
Cash paid for acquisitions of businesses	$ 72,760,000	$ 119,652,000
Goodwill	173,928,000	512,964,000				472,326,000
Contingent consideration					24,700,000
Business Acquisition, Transaction Costs	22,313,000
In process research and development
Business Acquisition [Line Items]
Recorded intangible assets					47,700,000
Navigate Energy Services L L C
Business Acquisition [Line Items]
Cash paid for acquisitions of businesses			37,500,000
Goodwill			15,800,000
KVS Transportation Inc
Business Acquisition [Line Items]
Total Consideration				149,000,000
Amount payable in future annual installments to acquire business				66,800,000
Number of annual installments				3
2TD Drilling
Business Acquisition [Line Items]
Cash paid for acquisitions of businesses					40,300,000
Additional contingent payments					$ 40,000,000