Significant Customers (Details)	12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Significant customers
Concentration percentage, disclosure threshold	5.00%
Customers | Sales
Significant customers
Concentration percentage	45.00%	42.40%
Customers | Receivables
Significant customers
Concentration percentage	18.40%	32.30%
Customers | Receivables | Customer 1
Significant customers
Concentration percentage	11.60%	10.50%
Customers | Receivables | Customer 2
Significant customers
Concentration percentage		8.30%
Customers | Receivables | Customer 3
Significant customers
Concentration percentage		8.30%
Customers | Receivables | Customer 4
Significant customers
Concentration percentage	6.80%
Customers | Receivables | Customer 5
Significant customers
Concentration percentage		5.20%
Precision Components Group | Customers | Sales | Customer 1
Significant customers
Concentration percentage	13.80%	10.20%
Precision Components Group | Customers | Sales | Customer 2
Significant customers
Concentration percentage	10.60%	9.40%
Precision Components Group | Customers | Sales | Customer 3
Significant customers
Concentration percentage	7.20%	8.10%
Stamping Group | Customers | Sales | Customer 4
Significant customers
Concentration percentage	6.70%	5.90%
Stamping Group | Customers | Sales | Customer 5
Significant customers
Concentration percentage	6.70%	8.80%