Segment Information (Details)	3 Months Ended
	Oct. 31, 2021 USD ($) ft²	Oct. 31, 2020 USD ($)	Jul. 31, 2021 USD ($)
Segment Reporting Information, Profit (Loss)
Net sales	$ 116,759,000	$ 135,218,000
Operating income (loss)	(6,515,000)	(85,716,000)
Net income (loss)	(5,984,000)	(85,840,000)
Benefit from income taxes	(2,053,000)	(2,239,000)
Change in fair value of convertible preferred stock purchase option liability	5,247,000	0
Interest (income) and other	219,000	66,000
Interest expense	1,607,000	2,297,000
Amortization of stock-based compensation	921,000	699,000
Amortization of intangibles	5,349,000	5,566,000
Depreciation	2,241,000	2,552,000
Proxy solicitation costs	2,162,000	0
Acquisition plan expenses	0	91,183,000
Restructuring costs	712,000
COVID-19 related costs	674,000
Adjusted EBITDA	5,544,000	14,284,000
Purchases of property, plant and equipment	3,638,000	890,000
Total assets	982,989,000	918,511,000	$ 993,111,000
Incremental interest expense on financing commitment letter	$ 1,178,000	1,178,000
Chandler, Arizona
Segment Reporting Information, Profit (Loss)
Area of property (in sq ft) | ft²	146,000
Commercial Solutions
Segment Reporting Information, Profit (Loss)
Net sales	$ 78,934,000	81,802,000
Government Solutions
Segment Reporting Information, Profit (Loss)
Net sales	37,825,000	53,416,000
Operating Segments | Commercial Solutions
Segment Reporting Information, Profit (Loss)
Net sales	78,934,000	81,802,000
Operating income (loss)	2,203,000	8,750,000
Net income (loss)	2,055,000	8,315,000
Benefit from income taxes	173,000	339,000
Change in fair value of convertible preferred stock purchase option liability	0
Interest (income) and other	(25,000)	96,000
Interest expense	0	0
Amortization of stock-based compensation	0	0
Amortization of intangibles	4,260,000	4,287,000
Depreciation	1,808,000	1,996,000
Proxy solicitation costs	0
Acquisition plan expenses		(1,052,000)
Restructuring costs	813,000
COVID-19 related costs	0
Adjusted EBITDA	9,084,000	13,981,000
Purchases of property, plant and equipment	2,696,000	389,000
Total assets	721,897,000	646,264,000
Operating Segments | Government Solutions
Segment Reporting Information, Profit (Loss)
Net sales	37,825,000	53,416,000
Operating income (loss)	(1,414,000)	2,585,000
Net income (loss)	(1,151,000)	2,691,000
Benefit from income taxes	(631,000)	(126,000)
Change in fair value of convertible preferred stock purchase option liability	0
Interest (income) and other	254,000	(40,000)
Interest expense	114,000	60,000
Amortization of stock-based compensation	0	0
Amortization of intangibles	1,089,000	1,279,000
Depreciation	381,000	403,000
Proxy solicitation costs	0
Acquisition plan expenses		0
Restructuring costs	(101,000)
COVID-19 related costs	674,000
Adjusted EBITDA	629,000	4,267,000
Purchases of property, plant and equipment	942,000	421,000
Total assets	235,048,000	238,172,000
Unallocated
Segment Reporting Information, Profit (Loss)
Net sales	0	0
Operating income (loss)	(7,304,000)	(97,051,000)
Net income (loss)	(6,888,000)	(96,846,000)
Benefit from income taxes	(1,595,000)	(2,452,000)
Change in fair value of convertible preferred stock purchase option liability	304,000
Interest (income) and other	(10,000)	10,000
Interest expense	1,493,000	2,237,000
Amortization of stock-based compensation		699,000
Amortization of intangibles	0	0
Depreciation	52,000	153,000
Proxy solicitation costs	2,162,000
Acquisition plan expenses		92,235,000
Restructuring costs	0
COVID-19 related costs	0
Adjusted EBITDA	(4,169,000)	(3,964,000)
Purchases of property, plant and equipment	0	80,000
Total assets	26,044,000	34,075,000
Intersegment Eliminations | Commercial Solutions
Segment Reporting Information, Profit (Loss)
Net sales	$ 1,132,000	$ 851,000