GOODWILL AND OTHER INTANGIBLE ASSETS (Details 3) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011
Expected amortization
2012	$ 14,124
2013	13,502
2014	12,729
2015	12,093
2016	11,277
Thereafter	73,553
Total	137,278
Peak Energy Services Ltd.'s ('Peak')
Acquired finite-lived intangible assets
Total Amount Assigned	12,657
Weighted Average Amortization Period (in years)	6.8
Other Acquisitions
Acquired finite-lived intangible assets
Total Amount Assigned	19,676
Weighted Average Amortization Period (in years)	13.4
Customer relationships | Peak Energy Services Ltd.'s ('Peak')
Acquired finite-lived intangible assets
Total Amount Assigned	9,503
Weighted Average Amortization Period (in years)	6.4
Customer relationships | Other Acquisitions
Acquired finite-lived intangible assets
Total Amount Assigned	16,697
Weighted Average Amortization Period (in years)	14.7
Other intangible assets | Peak Energy Services Ltd.'s ('Peak')
Acquired finite-lived intangible assets
Total Amount Assigned	3,154
Weighted Average Amortization Period (in years)	8.4
Other intangible assets | Other Acquisitions
Acquired finite-lived intangible assets
Total Amount Assigned	$ 2,979
Weighted Average Amortization Period (in years)	6.4