Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Operating activities:
Net income	$ 240,388	$ 193,490
Income (loss) from discontinued operations, net of tax	26	85
Income from continuing operations	240,362	193,405
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization	187,937	161,298
Deferred income taxes	49,222	42,428
Changes in current assets and liabilities, net of acquisitions:
Receivables	(238,373)	(55,749)
Inventories	2,480	(38,785)
Other current assets	(69,105)	(3,452)
Accounts payable	13,062	16,155
Other current liabilities	53,458	31,971
Other noncurrent changes	(35,361)	(27,170)
Net cash provided by continuing operations	203,682	320,101
Net cash used in discontinued operations	(579)	(2,720)
Net cash provided by operating activities	203,103	317,381
Investing activities:
Capital expenditures	(423,036)	(345,599)
Acquisitions, net of cash acquired	(53,263)	(27,858)
Net proceeds from sale or disposition of property and other	28,391	12,451
Investments	(717)	(1,560)
Net cash used in continuing operations	(448,625)	(362,566)
Net cash provided by discontinued operations	0	1,236
Net cash used in investing activities	(448,625)	(361,330)
Financing activities:
Issuance of short-term borrowings	169,977	0
Repayment of short-term borrowings	(30,000)	0
Issuance of long-term debt	302,724	356,952
Repayment of long-term debt	(166,956)	(157,315)
Proceeds from issuance of common stock	105,639	0
Dividends paid	(119,795)	(115,859)
Repurchase of common stock	0	(5,020)
Tax withholding on stock-based compensation	(3,015)	(2,330)
Net cash provided by financing activities	258,574	76,428
Effect of exchange rate changes on cash and cash equivalents	0	(1)
Increase in cash and cash equivalents	13,052	32,478
Cash and cash equivalents -- beginning of year	53,948	34,599
Cash and cash equivalents -- end of period	$ 67,000	$ 67,077