CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
OPERATING ACTIVITIES
Net income	$ 136,537	$ 62,018
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and other non-cash charges	50,570	39,863
Stock-based compensation expense	4,118	3,192
Gain on disposition of assets, net	(5,951)	(4,752)
Deferred income tax provision	4,401	7,788
Pension settlement charges	18,286
(Increase) decrease in assets:
Accounts receivable	23,017	(98,745)
Income taxes receivable	(10,745)	13,027
Inventories	(7,001)	(11,172)
Prepaid expenses	3,327	1,054
Other current assets	(297)	540
Other non-current assets	(833)	5,290
Increase (decrease) in liabilities:
Accounts payable	(30,646)	23,824
Income taxes payable	(95)	(128)
Accrued payroll and related expenses	(7,075)	8,881
Accrued insurance expenses	1,933	(4,530)
Accrued state, local and other taxes	2,121	3,077
Other accrued expenses	(2,938)	(2,351)
Pension and retirement plans liabilities	(5,068)	(4,429)
Long-term accrued insurance expenses	2,491	(1,840)
Other long-term liabilities	1,406	2,246
Net cash provided by operating activities	177,558	42,853
INVESTING ACTIVITIES
Capital expenditures	(104,488)	(50,578)
Proceeds from sale of assets	8,688	7,148
Purchase of business - advance (Note 16)	(78,982)
Net cash used for investing activities	(174,782)	(43,430)
FINANCING ACTIVITIES
Payment of dividends	(17,314)
Cash paid for common stock purchased and retired	(11,351)	(910)
Cash paid for finance lease		(2,713)
Net cash used for financing activities	(28,665)	(3,623)
Net decrease in cash and cash equivalents	(25,889)	(4,200)
Cash and cash equivalents at beginning of period	126,424	82,433
Cash and cash equivalents at end of period	100,535	78,233
Supplemental cash flows disclosure:
Income tax payments, net	48,553	872
Interest paid	83	123
Supplemental disclosure of noncash investing activities:
Capital expenditures included in accounts payable	$ 12,769	$ 8,248