Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Operating activities:
Net income	$ 124,833	$ 102,751
Loss from discontinued operations, net of tax	(548)	(1,483)
Income from continuing operations	125,381	104,234
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation, depletion and amortization	140,747	122,916
Deferred income taxes	2,881	22,753
Changes in current assets and liabilities, net of acquisitions:
Receivables	(40,801)	(171,304)
Inventories	(26,276)	(36,302)
Other current assets	30,790	(32,088)
Accounts payable	13,387	1,398
Other current liabilities	26,612	15,585
Other noncurrent changes	(10,923)	(50,822)
Net cash provided by (used in) continuing operations	261,798	(23,630)
Net cash provided by (used in) discontinued operations	(396)	735
Net cash provided by (used in) operating activities	261,402	(22,895)
Investing activities:
Capital expenditures	(248,800)	(281,674)
Acquisitions, net of cash acquired	(70,729)	(30,868)
Net proceeds from sale or disposition of property and other	22,968	8,197
Investments	23	(713)
Net cash used in investing activities	(296,538)	(305,058)
Financing activities:
Issuance of short-term borrowings	75,000	119,977
Repayment of short-term borrowings	0	(30,000)
Issuance of long-term debt	200,400	368,975
Repayment of long-term debt	(162,225)	(99,961)
Proceeds from issuance of common stock	3,410	69,565
Dividends paid	(83,188)	(79,570)
Tax withholding on stock-based compensation	(362)	(3,015)
Net cash provided by financing activities	33,035	345,971
Increase (decrease) in cash and cash equivalents	(2,101)	18,018
Cash and cash equivalents -- beginning of year	66,459	53,948
Cash and cash equivalents -- end of period	$ 64,358	$ 71,966