Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating activities:
Net income	$ 38,353	$ 31,763
Discontinued operations, net of tax	10	30
Income from continuing operations	38,343	31,733
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation, depletion and amortization	81,862	80,121
Deferred income taxes	8,856	(6,466)
Provision for credit losses	4,193	1,735
Amortization of debt issuance costs	380	341
Employee stock-based compensation costs	3,108	2,689
Pension and postretirement benefit plan net periodic benefit credit	(1,090)	(1,491)
Unrealized (gains) losses on investments	(3,957)	5,147
Gains on sales of assets	(4,361)	(3,136)
Changes in current assets and liabilities, net of acquisitions:
Receivables	14,969	(5,723)
Inventories	(40,885)	(44,080)
Other current assets	(58,308)	34,491
Accounts payable	(93,549)	2,980
Other current liabilities	16,715	13,086
Pension and postretirement benefit plan contributions	(159)	(149)
Other noncurrent changes	(9,794)	1,139
Net cash provided by (used in) continuing operations	(43,677)	112,417
Net cash provided by (used in) discontinued operations	29	(7)
Net cash provided by (used in) operating activities	(43,648)	112,410
Investing activities:
Capital expenditures	(154,049)	(150,288)
Acquisitions, net of cash acquired	0	(524)
Net proceeds from sale or disposition of property and other	7,282	4,586
Investments	(4,257)	(4,442)
Net cash used in investing activities	(151,024)	(150,668)
Financing activities:
Issuance of short-term borrowings	275,000	100,000
Repayment of short-term borrowings	(20,000)	0
Issuance of long-term debt	175,446	150,000
Repayment of long-term debt	(169,891)	(143,622)
Debt issuance costs	(114)	(718)
Net proceeds from issuance of common stock	0	(127)
Dividends paid	(45,246)	(44,229)
Repurchase of common stock	(4,811)	(7,399)
Tax withholding on stock-based compensation	(3,040)	(4,904)
Net cash provided by financing activities	207,344	49,001
Increase in cash and cash equivalents	12,672	10,743
Cash and cash equivalents -- beginning of year	80,517	54,161
Cash and cash equivalents -- end of period	$ 93,189	$ 64,904