Property And Equipment (Schedule Of Property, Plant And Equipment Under Capital Lease) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Property, Plant and Equipment [Line Items]
Property, plant and equipment under capital lease, gross	$ 157,063,000	$ 128,819,000
Less accumulated amortization	60,455,000	56,087,000
Property, plant and equipment under capital lease, net	96,608,000	72,732,000
Amortization of assets held under capital leases	22,000,000	21,200,000	20,400,000
Light Vehicles [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment under capital lease, gross	28,794,000	25,800,000
Well Service Units And Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment under capital lease, gross	1,671,000	1,791,000
Fluid Services Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment under capital lease, gross	83,544,000	65,874,000
Pressure Pumping Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment under capital lease, gross	24,260,000	18,293,000
Construction Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment under capital lease, gross	1,341,000	1,269,000
Software [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment under capital lease, gross	16,896,000	15,548,000
Other [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment under capital lease, gross	$ 557,000	$ 244,000