Restructuring And Related Costs (Narrative) (Details) - USD ($)	3 Months Ended	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Oct. 01, 2016	Oct. 03, 2015	Sep. 27, 2014
Restructuring Cost and Reserve [Line Items]
Restructuring expense		$ 4,079,000	$ 2,165,000	$ 0
2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense		0	1,237,000
2016 Restructuring Plan [Member] | Machida, Japan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense		1,036,000
Restructuring and related cost, incurred to date	$ 1,964,000	1,964,000
2014 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense		0	0	$ 0	$ 6,336,000
Employee Severance [Member] | 2017 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	2,899,000
Employee Severance [Member] | 2017 Restructuring Plan [Member] | Machida, Japan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	121,000
Employee Severance [Member] | 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense			$ 1,237,000
Employee Severance [Member] | 2016 Restructuring Plan [Member] | Machida, Japan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred to date	1,444,000	1,444,000
Facility Closing [Member] | 2017 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	23,000
Facility Closing [Member] | 2016 Restructuring Plan [Member] | Machida, Japan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred to date	520,000	520,000
2018 [Member] | Employee Severance [Member] | 2017 Restructuring Plan [Member] | Machida, Japan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost remaining	104,000	104,000
2018 [Member] | Minimum [Member] | 2017 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost remaining	1,000,000	1,000,000
2018 [Member] | Maximum [Member] | 2017 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost remaining	3,000,000	3,000,000
2019 [Member] | Employee Severance [Member] | 2017 Restructuring Plan [Member] | Machida, Japan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost remaining	$ 17,000	$ 17,000