Significant Customers (Details)	3 Months Ended		12 Months Ended
	Oct. 01, 2017	Oct. 02, 2016	Jun. 30, 2017
Significant customers
Concentration percentage, disclosure threshold	5.00%	5.00%
Customers | Sales
Significant customers
Concentration percentage	37.00%	39.40%
Customers | Receivables
Significant customers
Concentration percentage	32.50%		18.40%
Customers | Receivables | Customer 1
Significant customers
Concentration percentage	13.10%		11.60%
Customers | Receivables | Customer 2
Significant customers
Concentration percentage	7.00%		6.80%
Customers | Receivables | Customer 4
Significant customers
Concentration percentage	6.00%
Customers | Receivables | Customer 5
Significant customers
Concentration percentage	6.40%
Precision Components Group | Customers | Sales | Customer 1
Significant customers
Concentration percentage	10.20%	10.80%
Precision Components Group | Customers | Sales | Customer 4
Significant customers
Concentration percentage	6.00%	8.20%
Precision Components Group | Customers | Sales | Customer 5
Significant customers
Concentration percentage	5.50%	12.80%
Stamping Group | Customers | Sales | Customer 2
Significant customers
Concentration percentage	9.10%
Stamping Group | Customers | Sales | Customer 3
Significant customers
Concentration percentage	6.20%	7.60%