Condensed Consolidated Statements of Cash Flow (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities:
Net income	$ 53,804	$ 78,274
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	134,367	115,672
Accretion of asset retirement obligation	2,943	2,319
Stock-based compensation	6,840	7,060
Income attributable to sale of tax benefits, net of interest expense	(13,495)	(10,846)
Equity in losses (earnings) of investees	(1,796)	196
Mark-to-market of derivative instruments	1,096	(1,612)
Loss on disposal of property, plant and equipment	87	618
Loss (gain) on severance pay fund asset	(709)	(24)
Deferred income tax provision	(8,994)	25,522
Liability for unrecognized tax benefits	1,707	(2,000)
Other	267	0
Changes in operating assets and liabilities, net of businesses acquired:
Receivables	227	(5,753)
Costs and estimated earnings in excess of billings on uncompleted contracts	15,220	20,242
Inventories	(1,814)	565
Prepaid expenses and other	(13,966)	2,971
Change in operating lease right of use asset	2,322	2,695
Deposits and other	(3,468)	(1,277)
Accounts payable and accrued expenses	(30,320)	2,617
Billings in excess of costs and estimated earnings on uncompleted contracts	4,650	4,928
Liabilities for severance pay	(2,151)	(619)
Change in operating lease liabilities	(1,935)	(2,436)
Other long-term liabilities	(91)	(222)
Net cash provided by operating activities	144,791	238,890
Cash flows from investing activities:
Purchase of marketable securities	(49,320)	0
Maturities of marketable securities	3,565	0
Capital expenditures	(288,423)	(231,784)
Investment in unconsolidated companies	(6,208)	(14,794)
Cash paid for business acquisition, net of cash acquired	(171,000)	(43,321)
Decrease (increase) in severance pay fund asset, net of payments made to retired employees	2,352	529
Other investing activities	(911)	(3,600)
Net cash used in investing activities	(509,945)	(292,970)
Cash flows from financing activities:
Proceeds from long-term loans, net of transaction costs	275,000	419,262
Repayments of commercial paper and prepayment of loans	0	(50,000)
Proceeds from revolving credit lines with banks	0	1,249,400
Repayment of revolving credit lines with banks	0	(1,289,950)
Cash received from noncontrolling interest	5,390	7,577
Repayments of long-term debt	(58,357)	(115,606)
Stock issuance costs reimbursement	282	0
Cash paid to noncontrolling interest	(7,031)	(9,234)
Payments under finance lease obligations	(7,943)	(2,205)
Deferred debt issuance costs	(2,447)	(2,360)
Cash dividends paid	(19,882)	(16,892)
Net cash provided by financing activities	185,012	189,992
Effect of exchange rate changes	(336)	520
Net change in cash and cash equivalents and restricted cash and cash equivalents	(180,478)	136,432
Cash and cash equivalents and restricted cash and cash equivalents at beginning of period	536,778	153,110
Cash and cash equivalents and restricted cash and cash equivalents at end of period	356,300	289,542
Supplemental non-cash investing and financing activities:
Increase (decrease) in accounts payable related to purchases of property, plant and equipment	1,095	(995)
Right of use assets obtained in exchange for new lease liabilities	$ 5,579	$ 3,057