Restructuring And Related Costs (Summary Of Severance Charges On Statement Of Income) (Details) - USD ($)	12 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Oct. 03, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring expense	$ 4,079,000	$ 2,165,000	$ 0
Cost of Sales [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	3,140,000	1,061,000
Selling and Marketing Expense [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	315,000	284,000
General and Administrative Expense [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	624,000	815,000
Research and Development Expense [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	0	5,000
Test [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	2,922,000	847,000
Test [Member] | Cost of Sales [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	2,439,000	299,000
Test [Member] | Selling and Marketing Expense [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	112,000	129,000
Test [Member] | General and Administrative Expense [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	371,000	414,000
Test [Member] | Research and Development Expense [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	0	5,000
Sensors [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	1,157,000	1,318,000
Sensors [Member] | Cost of Sales [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	701,000	762,000
Sensors [Member] | Selling and Marketing Expense [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	203,000	155,000
Sensors [Member] | General and Administrative Expense [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	253,000	401,000
Sensors [Member] | Research and Development Expense [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	$ 0	$ 0