CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
ASSETS
Cash and cash equivalents	$ 73,189	$ 82,433
Accounts receivable, net of allowance for credit losses of $6,190 in 2022 and $5,717 in 2021	285,517	258,635
Inventories	84,381	78,983
Income taxes receivable	57,448	58,504
Prepaid expenses	13,545	9,773
Assets held for sale	692	692
Other current assets	2,430	2,990
Total current assets	517,202	492,010
Property, plant and equipment, less accumulated depreciation of $771,267 in 2022 and $788,922 in 2021	257,137	254,408
Operating lease right-of-use assets	23,741	24,572
Finance lease right-of-use assets	22,922	20,327
Goodwill	32,150	32,150
Other assets	38,016	40,898
Total assets	891,168	864,365
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable	76,974	74,404
Accrued payroll and related expenses	21,888	15,350
Accrued insurance expenses	5,380	10,129
Accrued state, local and other taxes	2,996	1,905
Income taxes payable	982	656
Current portion of operating lease liabilities	6,655	6,387
Current portion of finance lease liabilities	22,694	20,194
Other accrued expenses	1,663	1,824
Total current liabilities	139,232	130,849
Long-term accrued insurance expenses	10,628	11,770
Long-term pension liabilities	32,570	35,376
Deferred income taxes	24,787	17,749
Long-term operating lease liabilities	18,562	19,719
Other long-term liabilities	7,621	7,111
Total liabilities	233,400	222,574
Commitments and contingencies (Note 9)
STOCKHOLDERS' 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, 216,476,421 and 215,628,716 shares issued and outstanding in 2022 and 2021, respectively	21,648	21,563
Capital in excess of par value	0	0
Retained earnings	656,517	640,936
Accumulated other comprehensive loss	(20,397)	(20,708)
Total stockholders' equity	657,768	641,791
Total liabilities and stockholders' equity	$ 891,168	$ 864,365