Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2013

Property, Plant and Equipment

Schedule of property, plant and equipment at cost net of accumulated depreciation

December 31,	2013			2012
(in thousands)
Land	$	19,264		$	17,420
Buildings and leasehold improvements		130,072			111,986
Operating equipment		1,231,504			1,155,600
Computer software		17,121			20,581
Furniture and fixtures		7,737			7,232
Vehicles		387,854			357,913
Construction in progress		2,076			9,829
Gross property, plant and equipment		1,795,628			1,680,561
Less: accumulated depreciation		(1,069,321	)		(924,235	)
Net property, plant and equipment	$	726,307		$	756,326