CONSOLIDATED BALANCE SHEETS - USD ($)	Dec. 31, 2020	Dec. 31, 2019
ASSETS
Cash and cash equivalents	$ 84,496,000	$ 50,023,000
Accounts receivable, net	161,771,000	242,574,000
Inventories	82,918,000	100,947,000
Income taxes receivable	82,943,000	24,145,000
Prepaid expenses	9,124,000	10,459,000
Assets held for sale	4,032,000	5,385,000
Other current assets	3,075,000	3,325,000
Current assets	428,359,000	436,858,000
Property, plant and equipment, net	264,411,000	516,727,000
Operating lease right-of-use assets	27,270,000	33,850,000
Goodwill	32,150,000	32,150,000
Other assets	38,315,000	33,633,000
Total assets	790,505,000	1,053,218,000
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable	41,080,000	53,147,000
Accrued payroll and related expenses	18,428,000	19,641,000
Accrued insurance expenses	5,489,000	7,540,000
Accrued state, local and other taxes	2,788,000	2,427,000
Income taxes payable	1,115,000	1,534,000
Current portion of operating lease liabilities	9,192,000	10,625,000
Other accrued expenses	1,473,000	6,488,000
Current liabilities	79,565,000	101,402,000
Long-term accrued insurance expenses	11,822,000	14,040,000
Long-term pension liabilities	33,080,000	39,254,000
Deferred income taxes	13,332,000	37,319,000
Long-term operating lease liabilities	21,090,000	28,378,000
Other long-term liabilities	49,000	2,492,000
Total liabilities	158,938,000	222,885,000
Commitments and contingencies (Note 12)
STOCKHOLDER'S EQUITY
Preferred stock, $0.10 par value, 1,000,000 shares authorized, none issued
Common stock, $0.10 par value, 349,000,000 shares authorized, 214,951,093 and 214,422,979 shares issued and outstanding in 2020 and 2019, respectively	21,495,000	21,443,000
Capital in excess of par value	0	0
Retained earnings	627,778,000	832,113,000
Accumulated other comprehensive loss	(17,706,000)	(23,223,000)
Total stockholders' equity	631,567,000	830,333,000
Total liabilities and stockholders' equity	$ 790,505,000	$ 1,053,218,000