Segment Reporting (Details) - USD ($) $ in Thousands		12 Months Ended
		Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2017
Segment Reporting Information [Abstract]
Gross revenue		$ 88,510	$ 90,684	$ 96,083
Consolidated net (loss) income attributable to EEI		(554)	(308)	2,823
Depreciation and amortization expense		1,022	1,083	994
Assets		51,810	52,829
United States [Member]
Segment Reporting Information [Abstract]
Gross revenue		70,622	71,882	80,659
Consolidated net (loss) income attributable to EEI	[1]	(543)	(651)	3,688
Depreciation and amortization expense		800	800	800
Assets		43,842	43,823
United States [Member] | Government Contract [Member]
Segment Reporting Information [Abstract]
Gross revenue		14,100	15,800	21,900
South America [Member]
Segment Reporting Information [Abstract]
Gross revenue		17,888	18,802	15,424
Consolidated net (loss) income attributable to EEI	[2]	(11)	343	(865)
Depreciation and amortization expense		200	300	$ 200
Assets		$ 7,968	$ 9,006

[1] Includes depreciation and amortization expense of $0.8 million, $0.8 million and $0.8 million for fiscal years 2019, 2018 and 2017, respectively.

[2] Includes depreciation and amortization expense of $0.2 million, $0.3 million and $0.2 million for fiscal years 2019, 2018 and 2017, respectively.