Restructuring (narrative) (detail) - USD ($)	3 Months Ended			6 Months Ended		12 Months Ended
	Sep. 26, 2015	Jun. 27, 2015	Sep. 27, 2014	Sep. 26, 2015	Sep. 27, 2014	Mar. 31, 2015
Restructuring Cost and Reserve [Line Items]
Plant Restructuring	$ 15,000	$ (81,000)	$ 0	$ (66,000)	$ 0
Midwest Plant [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Equipment Cost						$ 1,376,000
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Plant Restructuring	15,000	(81,000)
Employee Severance [Member] | Midwest Plant [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Equipment Cost						842,000
Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Plant Restructuring	0	0
Other Restructuring [Member] | Midwest Plant [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Equipment Cost						270,000
Long Lived Asset Charges [Member]
Restructuring Cost and Reserve [Line Items]
Plant Restructuring	$ 0	$ 0
Long Lived Asset Charges [Member] | Midwest Plant [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Equipment Cost						$ 264,000