Restructuring and Related Costs (Summary of Restructuring Costs) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Apr. 01, 2017	Oct. 01, 2016	Apr. 01, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		$ 1,872,000	$ 944,000
2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 0		0
Machida, Japan [Member] | 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	381,000		944,000
Machida, Japan [Member] | Test [Member] | 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	0		0
Machida, Japan [Member] | Sensors [Member] | 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	381,000		944,000
Machida, Japan [Member] | Cost of sales | 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	254,000		580,000
Machida, Japan [Member] | Cost of sales | Test [Member] | 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	0		0
Machida, Japan [Member] | Cost of sales | Sensors [Member] | 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	254,000		580,000
Machida, Japan [Member] | Selling and Marketing Expense [Member] | 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	45,000		126,000
Machida, Japan [Member] | Selling and Marketing Expense [Member] | Test [Member] | 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	0		0
Machida, Japan [Member] | Selling and Marketing Expense [Member] | Sensors [Member] | 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	45,000		126,000
Machida, Japan [Member] | General and Administrative Expense [Member] | 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	82,000		238,000
Machida, Japan [Member] | General and Administrative Expense [Member] | Test [Member] | 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	0		0
Machida, Japan [Member] | General and Administrative Expense [Member] | Sensors [Member] | 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	82,000		238,000
Machida, Japan [Member] | Research and Development Expense [Member] | 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	0		0
Machida, Japan [Member] | Research and Development Expense [Member] | Test [Member] | 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	0		0
Machida, Japan [Member] | Research and Development Expense [Member] | Sensors [Member] | 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 0		$ 0