CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Cash flows from operating activities:
Net income	$ 276	$ 32,692
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	71,261	64,461
Amortization of premium from senior unsecured bonds	(72)
Accretion of asset retirement obligation	1,183	888
Stock-based compensation	5,000	4,637
Amortization of deferred lease income	(2,014)	(2,014)
Income attributable to sale of tax benefits, net of interest expense	(2,243)	(2,281)
Equity in income (losses) of investees	552	(942)
Impairment of auction rate securities	205
Loss on disposal of property, plant and equipment		571
Write-off of unsuccessful exploration activities		3,050
Return on investment in unconsolidated investments		3,734
Changes in unrealized loss in respect of derivative instruments, net	11,052
Gain (loss) on severance pay fund asset	282	(1,099)
Premium from issuance Senior Unsecured Bonds	1,957
Gain on sale of a subsidiary		(6,350)
Gain on acquisition of controlling interest		(36,928)
Deferred income tax provision (benefit)	(1,805)	5,717
Liability for unrecognized tax benefits	(1,186)	717
Deferred lease revenues	233	820
Changes in operating assets and liabilities, net of amounts acquired:
Receivables	2,556	(5,691)
Costs and estimated earnings in excess of billings on uncompleted contracts	2,628	13,869
Inventories	(5,361)	871
Prepaid expenses and other	(8,043)	(3,995)
Deposits and other	(471)	(253)
Accounts payable and accrued expenses	(9,592)	5,571
Due from/to related entities, net	(78)	(60)
Billings in excess of costs and estimated earnings on uncompleted contracts	32,511	1,420
Liabilities for severance pay	281	1,508
Other long-term liabilities	(719)	(1,091)
Due from/to Parent	121	(178)
Net cash provided by operating activities	98,514	79,644
Cash flows from investing activities:
Return of investment in unconsolidated investments		3,516
Purchases of marketable securities, net	(20,287)
Net change in restricted cash, cash equivalents and marketable securities	(36,884)	(23,352)
Cash received from sale of a subsidiary		19,594
Capital expenditures	(180,771)	(194,926)
Cash grant received from the U.S. Treasury under Section 1603 of the ARRA		108,286
Investment in unconsolidated companies	(305)	(511)
Cash paid for acquisition of controlling interest in a subsidiary, net of cash acquired		(64,517)
Intangible assets acquired		(875)
Increase (decrease) in severance pay fund asset, net of payments made to retired employees	61	(235)
Net cash used in investing activities	(238,186)	(153,020)
Cash flows from financing activities:
Proceeds from issuance of senior unsecured bonds	107,447	142,003
Proceeds from the sale of limited liability company interest in OPC LLC, net of transaction costs	24,878
Proceeds from revolving credit lines with banks	419,156	518,064
Repayment of revolving credit lines with banks	(387,300)	(535,600)
Repayments of long-term debt	(26,002)	(37,670)
Cash paid to non-controlling interest	(10,769)
Deferred debt issuance costs	(5,552)	(493)
Cash dividends paid	(5,924)	(9,995)
Net cash provided by financing activities	115,934	76,309
Net change in cash and cash equivalents	(23,738)	2,933
Cash and cash equivalents at beginning of period	82,815	46,307
Cash and cash equivalents at end of period	59,077	49,240
Supplemental non-cash investing and financing activities:
Increase in accounts payable related to purchases of property, plant and equipment	11,046	6,153
Accrued liabilities related to financing activities	$ 1,309