Operating Segment - Market Activity (Details)	3 Months Ended								12 Months Ended
	Mar. 27, 2016 USD ($)	Dec. 27, 2015 USD ($)	Sep. 27, 2015 USD ($)	Jun. 28, 2015 USD ($)	Mar. 29, 2015 USD ($)	Dec. 28, 2014 USD ($)	Sep. 28, 2014 USD ($)	Jun. 29, 2014 USD ($)	Mar. 27, 2016 USD ($) segment	Mar. 29, 2015 USD ($)	Mar. 30, 2014 USD ($)
Operating Segment
Number of reportable segment | segment									1
Market unit activity
Revenues	$ 114,154,100	$ 139,510,700	$ 142,353,300	$ 134,664,000	$ 112,962,200	$ 135,188,700	$ 148,521,800	$ 152,946,300	$ 530,682,100	$ 549,619,000	$ 560,086,600
Gross Profit	$ 23,018,900	$ 29,453,400	$ 30,511,700	$ 28,981,900	$ 24,311,800	$ 28,820,900	$ 32,361,000	$ 32,144,800	111,965,900	117,638,500	126,357,900
Public Carriers, Contractors & Program Managers
Market unit activity
Revenues									89,171,000	127,426,000	149,195,000
Gross Profit									15,155,000	20,915,000	27,708,000
Government System Operators
Market unit activity
Revenues									33,009,000	31,495,000	33,757,000
Gross Profit									7,713,000	7,535,000	7,791,000
Private System Operators
Market unit activity
Revenues									85,563,000	86,725,000	81,560,000
Gross Profit									20,601,000	20,866,000	21,475,000
Commercial Dealers & Resellers
Market unit activity
Revenues									129,986,000	134,195,000	140,552,000
Gross Profit									33,781,000	34,948,000	36,567,000
Retailer, Independent Dealer Agents & Carriers
Market unit activity
Revenues									192,953,000	169,778,000	155,023,000
Gross Profit									$ 34,716,000	$ 33,375,000	$ 32,817,000