Consolidated Statements of Equity - USD ($) shares in Thousands, $ in Thousands	Guadeloupe 1 [Member] Common Stock [Member]	Guadeloupe 1 [Member] Additional Paid-in Capital [Member]	Guadeloupe 1 [Member] Retained Earnings [Member]	Guadeloupe 1 [Member] AOCI Attributable to Parent [Member]	Guadeloupe 1 [Member] Parent [Member]	Guadeloupe 1 [Member] Noncontrolling Interest [Member]	Guadeloupe 1 [Member]	Tungsten [Member] Common Stock [Member]	Tungsten [Member] Additional Paid-in Capital [Member]	Tungsten [Member] Retained Earnings [Member]	Tungsten [Member] AOCI Attributable to Parent [Member]	Tungsten [Member] Parent [Member]	Tungsten [Member] Noncontrolling Interest [Member]	Tungsten [Member]	Ormat Nevada ORTP LLC [Member] Common Stock [Member]	Ormat Nevada ORTP LLC [Member] Additional Paid-in Capital [Member]	Ormat Nevada ORTP LLC [Member] Retained Earnings [Member]	Ormat Nevada ORTP LLC [Member] AOCI Attributable to Parent [Member]	Ormat Nevada ORTP LLC [Member] Parent [Member]	Ormat Nevada ORTP LLC [Member] Noncontrolling Interest [Member]	Ormat Nevada ORTP LLC [Member]	OPC LLC [Member] Common Stock [Member]	OPC LLC [Member] Additional Paid-in Capital [Member]	OPC LLC [Member] Retained Earnings [Member]	OPC LLC [Member] AOCI Attributable to Parent [Member]	OPC LLC [Member] Parent [Member]	OPC LLC [Member] Noncontrolling Interest [Member]	OPC LLC [Member]	U.S. Geothermal [Member] Common Stock [Member]	U.S. Geothermal [Member] Additional Paid-in Capital [Member]	U.S. Geothermal [Member] Retained Earnings [Member]	U.S. Geothermal [Member] AOCI Attributable to Parent [Member]	U.S. Geothermal [Member] Parent [Member]	U.S. Geothermal [Member] Noncontrolling Interest [Member]	U.S. Geothermal [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Parent [Member]	Noncontrolling Interest [Member]	Total
Balance (in shares) at Dec. 31, 2015																																				49,107
Balance at Dec. 31, 2015																																				$ 49	$ 849,223	$ 152,326	$ (8,164)	$ 993,434	$ 93,873	$ 1,087,307
Stock-based compensation																																					5,157			5,157		5,157
Exercise of options by employees and directors (in shares)																																				560
Exercise of options by employees and directors																																				$ 1	7,249			7,250		7,250
Cash paid to non controlling interest																																									(57,391)	(57,391)
Cash dividend declared																																						(25,682)		(25,682)		(25,682)
Increase in noncontrolling interest						$ 8,240	$ 8,240																																		3,697	3,697
Issuance of shares to noncontrolling interest, net of transaction costs																																					7,834			7,834	36,268	44,102
Net income																																						88,708		88,708	7,302	96,010
Currency translation adjustment																																							(1,241)	(1,241)	(407)	(1,648)
Loss in respect of derivative instruments designated for cash flow hedge																																							141	141		141
Change in unrealized gains or losses in respect of the Company's share in derivative instruments of unconsolidated investment																																							1,185	1,185		1,185
Amortization of unrealized gains in respect of derivative instruments designated for cash flow hedge																																							(96)	(96)		(96)
Currency translation adjustments																																							(1,241)	(1,241)	(407)	(1,648)
Balance (in shares) at Dec. 31, 2016																																				49,667
Balance at Dec. 31, 2016																																				$ 50	869,463	215,352	(8,175)	1,076,690	91,582	1,168,272
Stock-based compensation																																					8,760			8,760		8,760
Exercise of options by employees and directors (in shares)																																				942
Exercise of options by employees and directors																																				$ 1	16,111			16,112		16,112
Cash paid to non controlling interest																																									(21,313)	(21,313)
Cash dividend declared																																						(20,511)		(20,511)		(20,511)
Net income																																						132,414		132,414	13,643	146,057
Currency translation adjustment																																							2,603	2,603	837	3,440
Loss in respect of derivative instruments designated for cash flow hedge																																							135	135		135
Change in unrealized gains or losses in respect of the Company's share in derivative instruments of unconsolidated investment																																							804	804		804
Amortization of unrealized gains in respect of derivative instruments designated for cash flow hedge																																							(73)	(73)		(73)
Buyout of Class B membership																$ 2,913			$ 2,913	$ (6,964)	$ (4,051)		$ (8,469)			$ (8,469)	$ 6,537	$ (1,932)
Currency translation adjustments																																							2,603	2,603	837	3,440
Balance (in shares) at Dec. 31, 2017																																				50,609
Balance at Dec. 31, 2017																																				$ 51	888,778	327,255	(4,706)	1,211,378	84,322	1,295,700
Stock-based compensation																																					10,218			10,218		10,218
Exercise of options by employees and directors (in shares)																																				91
Exercise of options by employees and directors
Cash paid to non controlling interest																																									(10,972)	(10,972)
Cash dividend declared																																						(26,834)		(26,834)		(26,834)
Increase in noncontrolling interest						$ 5,339	$ 5,339						$ 996	$ 996
Net income																																						97,966		97,966	11,155	109,121
Currency translation adjustment																																							(1,352)	(1,352)	(479)	(1,831)
Loss in respect of derivative instruments designated for cash flow hedge																																							81	81		81
Change in unrealized gains or losses in respect of the Company's share in derivative instruments of unconsolidated investment																																							2,235	2,235		2,235
Amortization of unrealized gains in respect of derivative instruments designated for cash flow hedge																																							(57)	(57)		(57)
Buyout of Class B membership																$ 2,900				$ (7,000)			(8,500)				6,500
Cumulative effect of changes in accounting principles at Dec. 31, 2017																																						23,835		23,835		23,835
Adjusted balance as of the beginning of the year at Dec. 31, 2017																																				51	888,778	351,090	(4,706)	1,235,213	84,322	1,319,535
Tax effect of partnership interest buyout																							$ 2,367			$ 2,367		$ 2,367
Purchase of USG																																		$ 34,898	$ 34,898
Currency translation adjustments																																							(1,352)	(1,352)	(479)	(1,831)
Balance (in shares) at Dec. 31, 2018																																				50,700
Balance at Dec. 31, 2018																																				$ 51	$ 901,363	$ 422,222	$ (3,799)	$ 1,319,837	$ 125,259	$ 1,445,096