CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
ASSETS
Cash and cash equivalents	$ 212,199	$ 223,310
Accounts receivable, net of allowance for credit losses of $5,634 in 2024 and $7,109 in 2023	329,654	324,915
Inventories	112,306	110,904
Income taxes receivable	46,269	52,269
Prepaid expenses	10,371	12,907
Other current assets	2,535	2,768
Total current assets	713,334	727,073
Property, plant and equipment, less accumulated depreciation of $826,048 in 2024 and $810,933 in 2023	457,751	435,139
Operating lease right-of-use assets	25,402	24,537
Finance lease right-of-use assets	972	1,036
Goodwill	50,824	50,824
Other intangibles, net	12,302	12,825
Retirement plan assets	28,011	26,772
Other assets	8,637	8,639
Total assets	1,297,233	1,286,845
LIABILITIES
Accounts payable	106,836	85,036
Accrued payroll and related expenses	20,780	30,956
Accrued insurance expenses	5,710	5,340
Accrued state, local and other taxes	4,198	4,461
Income taxes payable	1,610	275
Unearned revenue	572	15,743
Current portion of operating lease liabilities	7,741	7,367
Current portion of finance lease liabilities and finance obligations	253	375
Accrued expenses and other liabilities	2,336	2,304
Total current liabilities	150,036	151,857
Long-term accrued insurance expenses	10,602	10,202
Retirement plan liabilities	24,037	23,724
Deferred income taxes	52,020	51,290
Long-term operating lease liabilities	18,518	18,600
Long-term finance lease liabilities	756	819
Other long-term liabilities	7,974	7,840
Total liabilities	263,943	264,332
Commitments and contingencies (Note 12)
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, 214,347,063 and 215,026,458 shares issued and outstanding in 2024 and 2023, respectively	21,434	21,502
Capital in excess of par value	0	0
Retained earnings	1,014,338	1,003,380
Accumulated other comprehensive loss	(2,482)	(2,369)
Total stockholders' equity	1,033,290	1,022,513
Total liabilities and stockholders' equity	$ 1,297,233	$ 1,286,845