Consolidated Statements Of Operations And Comprehensive Income (Loss) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Revenues:
Electricity	$ 327,529		$ 323,849		$ 291,820
Product	186,879		113,160		81,410
Total consolidated revenues	514,408	[1]	437,009	[1]	373,230	[1]
Cost of revenues:
Electricity	244,634		244,037		242,326
Product	135,346		76,072		53,277
Total cost of revenues	379,980		320,109		295,603
Gross margin	134,428		116,900		77,627
Operating expenses:
Research and development expenses	6,108		8,801		10,120
Selling and marketing expenses	16,122		16,207		13,447
General and administrative expenses	28,267		27,885		27,442
Impairment charges	236,377
Write-off of unsuccessful exploration activities	2,639				3,050
Operating income (loss)	(155,085)		64,007		23,568
Other income (expense):
Interest income	1,201		1,427		343
Interest expense, net	(64,069)		(69,459)		(40,473)
Foreign currency translation and transaction gains (losses)	242		(1,350)		1,557
Income attributable to sale of tax benefits	10,127		11,474		8,729
Gain on acquisition of controlling interest					36,928
Other non-operating income, net	590		671		130
Income (loss) from continuing operations, before income taxes and equity in income (losses) of investees	(206,994)		6,770		30,782
Income tax benefit (provision)	3,500		(48,535)		1,098
Equity in income (losses) of investees, net	(2,522)		(959)		998
Income (loss) from continuing operations	(206,016)		(42,724)		32,878
Discontinued operations:
Income from discontinued operations, net of related tax of $0					14
Gain on sale of a subsidiary in New Zealand, net of related tax of $2,000					4,336
Net income (loss)	(206,016)		(42,724)		37,228
Net loss (income) attributable to noncontrolling interest	(414)		(332)		90
Net income (loss) attributable to the Company's stockholders	(206,430)		(43,056)		37,318
Comprehensive income (loss):
Net income (loss)	(206,016)		(42,724)		37,228
Other comprehensive income, net of related taxes:
Currency translation adjustment					43
Amortization of unrealized gains in respect of derivative instruments designated for cash flow hedge	(190)		(212)		(234)
Change in unrealized gains or losses on marketable securities available-for-sale	246		(237)		(80)
Comprehensive income (loss)	(205,960)		(43,173)		36,957
Comprehensive loss (income) attributable to noncontrolling interest	(414)		(332)		90
Comprehensive income (loss) attributable to the Company's stockholders	$ (206,374)		$ (43,505)		$ 37,047
Basic:
Income (loss) from continuing operations	$ (4.54)		$ (0.95)		$ 0.72
Discontinued operations					$ 0.10
Net income (loss)	$ (4.54)		$ (0.95)		$ 0.82
Diluted:
Income (loss) from continuing operations	$ (4.54)		$ (0.95)		$ 0.71
Discontinued operations					$ 0.10
Net income (loss)	$ (4.54)		$ (0.95)		$ 0.82
Weighted average number of shares used in computation of earnings (loss) per share attributable to the Company's stockholders:
Basic	45,431		45,431		45,431
Diluted	45,431		45,431		45,452
Dividend per share declared	$ 0.08		$ 0.13		$ 0.27

[1] Revenues as reported in the geographic area in which they originate.