Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2019

Property Plant And Equipment [Abstract]

Schedule of Property, Plant and Equipment

	Average	December 31,
	useful lives  (1)	2019		2018
		(In Thousands)
Machinery, equipment and automotive	25	$	1,204,695	$	1,189,438
Buildings and improvements	26		38,810		39,032
Land improvements	34		8,223		8,076
Furniture, fixtures and store equipment	3		1,122		1,122
Construction in progress	N/A		31,575		28,753
Capital spare parts	N/A		24,245		28,945
Land	N/A		4,575		4,583
			1,313,245		1,299,949
Less accumulated depreciation and    amortization			376,771		325,701
		$	936,474	$	974,248

(1) Weighted average useful lives as of December 31, 2019.