Segment Information (Details) - USD ($)	3 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Jul. 31, 2017
Segment Reporting Information [Line Items]
Net sales	$ 121,569,000	$ 135,786,000
Operating income (loss)	222,000	(728,000)
Net income (loss)	(1,660,000)	(2,489,000)
Provision for (benefit from) income taxes	(745,000)	(1,562,000)
Interest (income) and other expense	39,000	(2,000)
Interest expense	2,588,000	3,325,000
Amortization of stock-based compensation	747,000	970,000
Amortization of intangibles	5,269,000	6,055,000
Depreciation	3,346,000	3,749,000
Adjusted EBITDA	9,584,000	10,046,000
Purchases of property, plant and equipment	1,108,000	2,075,000
Total assets	826,232,000	903,452,000	$ 832,063,000
Secured Credit Facility
Segment Reporting Information [Line Items]
Interest expense related to Credit Facility	2,465,000	3,175,000
Unallocated
Segment Reporting Information [Line Items]
Net sales	0	0
Operating income (loss)	(3,929,000)	(6,326,000)
Net income (loss)	(5,720,000)	(8,005,000)
Provision for (benefit from) income taxes	(751,000)	(1,585,000)
Interest (income) and other expense	(7,000)	3,000
Interest expense	2,549,000	3,261,000
Amortization of stock-based compensation	747,000	970,000
Amortization of intangibles	0	0
Depreciation	286,000	411,000
Adjusted EBITDA	(2,896,000)	(4,945,000)
Purchases of property, plant and equipment	56,000	70,000
Total assets	43,844,000	68,921,000
Commercial Solutions Segment | Operating Segments
Segment Reporting Information [Line Items]
Net sales	76,114,000	76,178,000
Operating income (loss)	4,792,000	3,098,000
Net income (loss)	4,702,000	3,013,000
Provision for (benefit from) income taxes	6,000	23,000
Interest (income) and other expense	48,000	(2,000)
Interest expense	36,000	64,000
Amortization of stock-based compensation	0	0
Amortization of intangibles	4,425,000	4,436,000
Depreciation	2,444,000	2,587,000
Adjusted EBITDA	11,661,000	10,121,000
Purchases of property, plant and equipment	959,000	1,995,000
Total assets	600,649,000	623,510,000
Commercial Solutions Segment | Intersegment Eliminations
Segment Reporting Information [Line Items]
Intersegment sales	2,621,000	3,426,000
Government Solutions Segment | Operating Segments
Segment Reporting Information [Line Items]
Net sales	45,455,000	59,608,000
Operating income (loss)	(641,000)	2,500,000
Net income (loss)	(642,000)	2,503,000
Provision for (benefit from) income taxes	0	0
Interest (income) and other expense	(2,000)	(3,000)
Interest expense	3,000	0
Amortization of stock-based compensation	0	0
Amortization of intangibles	844,000	1,619,000
Depreciation	616,000	751,000
Adjusted EBITDA	819,000	4,870,000
Purchases of property, plant and equipment	93,000	10,000
Total assets	$ 181,739,000	$ 211,021,000