SEGMENT REPORTING Reconciliation of Segment Income (Loss) to Consolidated Net Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011
Segment Reporting [Abstract]
Share based compensation in unallocated costs	$ 127		$ 50		$ 309		$ 315
Income tax benefit associated with net operating loss carryback	1,500						2,600
Income tax benefit associated with recognition of deferred tax assets			12,000				12,000
Total net loss before income taxes for reportable segments	(3,966)		(886)		(9,472)		(3,468)
Other operational segment net income (loss) before income taxes	147		(55)		82		180
Total segment net income (loss) before income taxes	(3,819)		(941)		(9,390)		(3,288)
Unallocated cost of corporate, DSIT and OmniMetrix headquarters	(1,694)	[1]	(845)	[1]	(4,863)	[1]	(2,535)	[1]
Income Tax Expense (Benefit)	1,487	[2]	12,111		2,476	[2]	12,072
Net Income (Loss) Attributable to Noncontrolling Interest	276		181		737		484
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	0		(393)		0		(1,408)
Gain on sale of HangXing	0		0		0		492
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax	0		30,683		0		30,683
Loss from Discontinued Operations, Net of Income Taxes							(28,735)
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Noncontrolling Interest	0		(151)		0		(540)
Net Income (Loss) Attributable to Acorn Energy, Inc. Shareholders	$ (3,750)		$ 40,796		$ (11,040)		$ 36,500

[1] * Includes stock compensation expense of $315 and $309 for the nine month periods ending September 30, 2011 and 2012, respectively. Includes stock compensation expense of $50 and $127 for the three month periods ending September 30, 2011 and 2012, respectively.

[2] ** In the nine months ended September 30, 2012, includes an income tax benefit of $2,600 recorded with respect to net operating loss carryback of the Company's expected consolidated tax loss in the United States. In the three months ended September 30, 2012, includes an income tax benefit of $1,500 recorded with respect to net operating loss carryback of the Company's expected consolidated tax loss in the United States. In the three and nine month periods ended September 30, 2011, relates primarily to the recognition of deferred tax assets of $12,000 following the gain on the sale of CoaLogix.