Acquisitions (Schedule Of Final Values At The Date Of Acquisition) (Details) (USD $) In Thousands, unless otherwise specified				12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2009 Team Snubbing Services, Inc. [Member]	Dec. 31, 2010 Rocky Mountain Cementers, Inc. [Member]	Dec. 31, 2010 New Tech Systems, Inc [Member]	Dec. 31, 2010 Taylor Rig, LLC [Member]	Dec. 31, 2010 Platinum Pressure Services, Inc. [Member]	Dec. 31, 2011 Lone Star Anchor Trucking, Inc [Member]	Dec. 31, 2011 Maverick [Member]	Dec. 31, 2011 Pat's P&A, Inc. [Member]	Dec. 31, 2011 Cryogas Services LLP [Member]
Business Acquisition [Line Items]
Closing Date				December 28, 2009	March 1, 2010	April 20, 2010	May 3, 2010	December 16, 2010	July 7, 2011	July 8, 2011	August 1, 2011	September 8, 2011
Total Cash Paid (net of cash acquired)	$ 218,338	$ 50,263	$ 6,985	$ 6,985	$ 687	$ 900	$ 8,734	$ 39,942	$ 10,102	$ 186,251	$ 10,900	$ 11,085