Business Segments - Segment Activity (Details)	3 Months Ended		9 Months Ended
	Dec. 29, 2019 USD ($)	Dec. 30, 2018 USD ($)	Dec. 29, 2019 USD ($) segment product	Dec. 30, 2018 USD ($)
Business Segments
Number of reportable segment | segment			2
Number of product categories | product			4
Market unit activity
Revenues	$ 139,578,200	$ 152,294,500	$ 412,118,400	$ 461,850,000
Gross Profit	23,074,300	30,998,700	74,657,100	93,091,500
(Loss) income before provision for (benefit from) income taxes	(6,341,800)	3,256,000	(9,632,500)	6,491,000
Segments
Market unit activity
Directly allocable expenses	10,893,000	12,117,000	34,357,000	37,113,000
(Loss) income before provision for (benefit from) income taxes	12,181,000	18,882,000	40,300,000	55,979,000
Corporate
Market unit activity
Directly allocable expenses	18,523,000	15,626,000	49,933,000	49,488,000
Public carrier
Market unit activity
Revenues	37,793,000	33,593,000	110,448,000	113,647,000
Gross Profit	4,508,000	4,583,000	13,621,000	14,989,000
Value-added resellers and integrators
Market unit activity
Revenues	63,051,000	65,373,000	192,727,000	199,570,000
Gross Profit	15,139,000	16,013,000	46,432,000	48,842,000
Retail
Market unit activity
Revenues	38,734,000	53,329,000	108,943,000	148,633,000
Gross Profit	3,427,000	10,403,000	14,604,000	29,261,000
Commercial Segment
Market unit activity
Revenues	100,844,000	98,966,000	303,175,000	313,217,000
Gross Profit	19,647,000	20,596,000	60,053,000	63,831,000
Commercial Segment | Segments
Market unit activity
Directly allocable expenses	7,620,000	8,079,000	25,058,000	24,722,000
(Loss) income before provision for (benefit from) income taxes	12,027,000	12,517,000	34,995,000	39,109,000
Commercial Segment | Public carrier
Market unit activity
Revenues	37,793,000	33,593,000	110,448,000	113,647,000
Gross Profit	4,508,000	4,583,000	13,621,000	14,989,000
Commercial Segment | Value-added resellers and integrators
Market unit activity
Revenues	63,051,000	65,373,000	192,727,000	199,570,000
Gross Profit	15,139,000	16,013,000	46,432,000	48,842,000
Retail Segment
Market unit activity
Revenues	38,734,000	53,329,000	108,943,000	148,633,000
Gross Profit	3,427,000	10,403,000	14,604,000	29,261,000
Retail Segment | Segments
Market unit activity
Directly allocable expenses	3,273,000	4,038,000	9,299,000	12,391,000
(Loss) income before provision for (benefit from) income taxes	154,000	6,365,000	5,305,000	16,870,000
Retail Segment | Retail
Market unit activity
Revenues	38,734,000	53,329,000	108,943,000	148,633,000
Gross Profit	$ 3,427,000	$ 10,403,000	$ 14,604,000	$ 29,261,000