CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
OPERATING ACTIVITIES
Net income	$ 154,854	$ 131,358
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and other non-cash charges	78,758	61,352
Stock-based compensation expense	6,033	4,764
Gain on disposition of assets, net	(7,729)	(6,295)
Deferred income tax provision	7,845	13,284
Pension settlement charges	18,286
(Increase) decrease in assets:
Accounts receivable	102,591	(211,375)
Income taxes receivable	(20,486)	13,038
Inventories	(11,506)	(14,708)
Prepaid expenses	6,437	2,907
Other current assets	(167)	(83)
Other non-current assets	(2,341)	6,393
Increase (decrease) in liabilities:
Accounts payable	(31,569)	42,700
Income taxes payable	(240)	(139)
Accrued payroll and related expenses	(5,245)	10,759
Accrued insurance expenses	3,528	(5,702)
Accrued state, local and other taxes	1,900	4,309
Accrued expenses and other liabilities	(4,385)	(2,804)
Pension and retirement plans liabilities	(6,696)	(6,044)
Long-term accrued insurance expenses	2,340	(3,762)
Other long-term liabilities	6,934	976
Net cash provided by operating activities	299,142	40,928
INVESTING ACTIVITIES
Capital expenditures	(148,816)	(90,227)
Proceeds from sale of assets	12,569	11,572
Purchase of business	(78,798)
Net cash used for investing activities	(215,045)	(78,655)
FINANCING ACTIVITIES
Payment of dividends	(25,948)	(4,267)
Cash paid for common stock purchased and retired	(12,445)	(912)
Cash paid for finance lease and finance obligations	(254)	(3,642)
Net cash used for financing activities	(38,647)	(8,821)
Net increase (decrease) in cash and cash equivalents	45,450	(46,548)
Cash and cash equivalents at beginning of period	126,424	82,433
Cash and cash equivalents at end of period	171,874	35,885
Supplemental cash flows disclosure:
Income tax payments, net	61,484	18,615
Interest paid	124	127
Supplemental disclosure of noncash investing activities:
Capital expenditures included in accounts payable	$ 9,527	$ 13,912