Income Taxes (Details) - USD ($) $ in Thousands	5 Months Ended	7 Months Ended	12 Months Ended
	Dec. 31, 2017	Jul. 31, 2018	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2016
Income Taxes [Abstract]
Statutory federal tax rate	34.00%	21.00%	26.50%	34.00%	34.00%
Federal tax expense			$ 300
Net federal tax expense			100
One-time transition tax			500
Benefit from outstanding unpaid dividends from a foreign subsidiary			400
Income before income tax provision [Abstract]
U.S. operations			(948)	$ 4,758	$ 4,478
Foreign operations (primarily South American operations)			1,102	(80)	(1,178)
Income before income tax provision			154	4,678	3,300
Current [Abstract]
Federal			(62)	(149)	1,155
State			26	42	177
Foreign			228	282	577
Total current			192	175	1,909
Deferred [Abstract]
Federal			289	1,653	663
State			(75)	308	270
Foreign			(148)	31	304
Total deferred			66	1,992	1,237
Total income tax provision			258	2,167	3,146
Reconciliation of income tax provision from statutory U.S. income tax rate to the effective income tax rate [Abstract]
Income tax provision (benefit) at the U.S. federal statutory income tax rate			41	1,590	1,122
Tax on Foreign Earnings			129	0	0
Change in Tax Rates under Tax Act			322	0	0
International rate differences			27	33	(10)
Peru non-deductible expenses			14	53	59
Foreign dividend income			0	240	263
Income from "pass-through" entities taxable to noncontrolling partners			0	(1)	(39)
Re-evaluation and settlements of tax contingencies			0	(33)	0
Change in valuation allowance			(19)	98	1,582
State taxes, net of federal benefit			(32)	200	312
Other foreign taxes, net of federal benefit			(95)	(111)	(277)
Other permanent differences			(129)	98	134
Total income tax provision			258	2,167	3,146
Deferred tax assets [Abstract]
Net operating loss carryforwards						$ 1,081	$ 1,470
Accrued compensation and expenses						611	752
Federal benefit from foreign accounting differences						460	435
Contract and other reserves						311	463
Foreign tax credit						296	296
Capital loss carryforwards						143	217
Foreign and state income taxes						0	17
Other						202	376
Deferred tax assets						3,104	4,026
Less: Valuation allowance	$ (2,020)	$ (2,006)	(2,006)	(2,020)	(2,278)	(2,006)	(2,020)	$ (2,278)
Net deferred tax assets						1,098	2,006
Deferred tax liabilities [Abstract]
Fixed assets and intangibles						(39)	(102)
Federal expense on state deferred taxes						(60)	(74)
Federal expense from foreign accounting differences						(7)	(332)
Unremitted foreign earnings						(206)	(623)
Other						3	(26)
Net deferred tax liabilities						(309)	(1,157)
Foreign operating loss carryforwards						2,800
State operating loss carryforwards						2,000
Deferred tax assets valuation allowance [Abstract]
Balance at beginning of period	2,020		2,020	2,278
Additions during the period			60	2
Reductions during period			(74)	(260)
Balance at end of period		$ 2,006	2,006	2,020	2,278
Amount of undistributed income that will not be indefinitely reinvested in foreign operations						200	600	700
Undistributed foreign earnings	$ 5,600
Foreign earnings			1,000
Maximum [Member]
Uncertain tax positions [Abstract]
Uncertain tax positions						$ 100	$ 100	$ 100
Interest accrued related to liabilities for uncertain tax positions			$ 100	$ 100	$ 100
IRS [Member]
Income Tax Examination [Abstract]
Income tax examination, year subject to examination			2018 2017 2016 2015
State, Local and Foreign [Member]
Income Tax Examination [Abstract]
Income tax examination, year subject to examination			2017 2016 2015 2014