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The aggregate total costs related to selling a firm's product and services, as well as all other general and administrative expenses. Also includes the net amount of nonoperating interest (income) expense.

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Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

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Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Operating Segments - Market Activity (Details)	3 Months Ended								12 Months Ended
Operating Segments - Market Activity (Details)	Mar. 31, 2019 USD ($)	Dec. 30, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jul. 01, 2018 USD ($)	Apr. 01, 2018 USD ($)	Dec. 24, 2017 USD ($)	Sep. 24, 2017 USD ($)	Jun. 25, 2017 USD ($)	Mar. 31, 2019 USD ($) segment product	Apr. 01, 2018 USD ($)	Mar. 26, 2017 USD ($)
Business Segments
Number of reportable segment \| segment									2
Number of product categories \| product									4
Market unit activity
Revenues	$ 144,963,800	$ 152,294,500	$ 158,636,100	$ 150,919,400	$ 148,920,100	$ 146,260,300	$ 145,083,500	$ 140,010,800	$ 606,813,800	$ 580,274,700	$ 533,295,100
Gross Profit	28,267,200	30,998,700	31,394,700	30,698,100	31,538,700	29,599,800	29,923,100	29,166,800	121,358,700	120,228,400	111,767,800
Income before provision for income taxes	$ 800,200	$ 3,256,000	$ 1,672,600	$ 1,562,400	$ 1,091,600	$ 2,072,100	$ 3,092,200	$ 1,216,700	7,291,200	7,472,600	2,486,300
Segments
Market unit activity
Directly allocable expenses									49,627,000	48,127,000	48,854,000
Income before provision for income taxes									71,732,000	72,101,000	62,914,000
Corporate
Market unit activity
Directly allocable expenses									64,441,000	64,628,000	60,428,000
Public Carrier
Market unit activity
Revenues									156,983,000	115,061,000	82,015,000
Gross Profit									20,275,000	16,707,000	13,706,000
Value-added resellers and integrators
Market unit activity
Revenues									262,062,000	270,615,000	249,670,000
Gross Profit									64,130,000	64,620,000	61,838,000
Retail
Market unit activity
Revenues									187,769,000	194,599,000	201,610,000
Gross Profit									36,954,000	38,901,000	36,224,000
Commercial Segment
Market unit activity
Revenues									419,045,000	385,676,000	331,685,000
Gross Profit									84,405,000	81,327,000	75,544,000
Commercial Segment \| Segments
Market unit activity
Directly allocable expenses									33,475,000	32,592,000	32,455,000
Income before provision for income taxes									50,930,000	48,735,000	43,089,000
Commercial Segment \| Public Carrier
Market unit activity
Revenues									156,983,000	115,061,000	82,015,000
Gross Profit									20,275,000	16,707,000	13,706,000
Commercial Segment \| Value-added resellers and integrators
Market unit activity
Revenues									262,062,000	270,615,000	249,670,000
Gross Profit									64,130,000	64,620,000	61,838,000
Retail Segment
Market unit activity
Revenues									187,769,000	194,599,000	201,610,000
Gross Profit									36,954,000	38,901,000	36,224,000
Retail Segment \| Segments
Market unit activity
Directly allocable expenses									16,152,000	15,535,000	16,399,000
Income before provision for income taxes									20,802,000	23,366,000	19,825,000
Retail Segment \| Retail
Market unit activity
Revenues									187,769,000	194,599,000	201,610,000
Gross Profit									$ 36,954,000	$ 38,901,000	$ 36,224,000