Segment Reporting (Details) - USD ($) $ in Thousands		12 Months Ended
		Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2016
Segment Reporting Information [Abstract]
Gross revenue		$ 90,684	$ 96,083	$ 98,248
Assets		52,829	57,917
Consolidated net (loss) income attributable to EEI		(308)	2,823	741
Depreciation and amortization expense		1,083	994	1,042
United States [Member]
Segment Reporting Information [Abstract]
Gross revenue		71,882	80,659	82,794
Assets		43,823	48,011
Consolidated net (loss) income attributable to EEI	[1]	(651)	3,688	2,473
Depreciation and amortization expense		800	800	900
United States [Member] | Government Contract [Member]
Segment Reporting Information [Abstract]
Gross revenue		15,800	21,900	25,300
South America [Member]
Segment Reporting Information [Abstract]
Gross revenue		18,802	15,424	15,454
Assets		9,006	9,906
Consolidated net (loss) income attributable to EEI	[2]	343	(865)	(1,732)
Depreciation and amortization expense		$ 300	$ 200	$ 100

[1] Includes depreciation and amortization expense of $0.8 million, $0.8 million and $0.9 million for fiscal years 2018, 2017 and 2016, respectively.

[2] Includes depreciation and amortization expense of $0.3 million, $0.2 million and $0.1 million for fiscal years 2018, 2017 and 2016, respectively.