Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2012

Schedule of Property, Plant and Equipment

	Useful lives		December 31,
	in years		2012		2011
			(In Thousands)
Machinery, equipment and automotive		3 – 30	$	253,317	$	239,322
Proved natural gas properties		*		49,801		—
Buildings and improvements		8 – 30		44,248		39,381
Furniture, fixtures and store equipment		3 – 10		6,718		5,926
Assets under capital leases		10		1,468		2,105
Land improvements		10		1,148		1,080
Construction in progress		N/A		52,673		23,714
Capital spare parts		N/A		5,430		7,407
Land		N/A		10,386		7,242
				425,189		326,177
Less accumulated depreciation, depletion and amortization				143,318		161,630
			$	281,871	$	164,547