CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
OPERATING ACTIVITIES
Net income	$ 71,524	$ 15,079
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and other non-cash charges	24,131	19,343
Stock-based compensation expense	1,802	1,497
Gain on disposition of assets, net	(2,936)	(2,954)
Deferred income tax provision	2,536	6,975
Pension settlement charge	17,375
(Increase) decrease in assets:
Accounts receivable	16,209	(26,586)
Income taxes receivable	18,057	1,056
Inventories	(959)	(5,326)
Prepaid expenses	1,725	(3,771)
Other current assets	141	677
Other non-current assets	(236)	2,875
Increase (decrease) in liabilities:
Accounts payable	(3,389)	(168)
Income taxes payable	14	326
Accrued payroll and related expenses	(13,193)	6,529
Accrued insurance expenses	865	(4,749)
Accrued state, local and other taxes	1,691	1,091
Other accrued expenses	(1,074)	(1,746)
Pension and retirement plans liabilities	(4,723)	(2,548)
Long-term accrued insurance expenses	2,018	(1,142)
Other long-term liabilities	945	1,790
Net cash provided by operating activities	132,523	8,248
INVESTING ACTIVITIES
Capital expenditures	(65,300)	(19,084)
Proceeds from sale of assets	4,285	3,825
Net cash used for investing activities	(61,015)	(15,259)
FINANCING ACTIVITIES
Payment of dividends	(8,679)
Cash paid for common stock purchased and retired	(11,349)	(910)
Cash paid for finance lease		(1,323)
Net cash used for financing activities	(20,028)	(2,233)
Net increase (decrease) in cash and cash equivalents	51,480	(9,244)
Cash and cash equivalents at beginning of period	126,424	82,433
Cash and cash equivalents at end of period	177,904	73,189
Supplemental cash flows disclosure:
Income tax payments (refunds), net	922	(333)
Interest paid	41	43
Supplemental disclosure of noncash investing activities:
Capital expenditures included in accounts payable	$ 11,866	$ 7,020