Restructuring and Related Costs Restructuring and Related Costs (Restructuring Reserve Rollforward) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Restructuring Reserve [Roll Forward]
Balance, September 30, 2017			$ 3,962
Restructuring expense	$ 735	$ 92	1,343	$ 1,036
Payments			(1,807)
Other adjustments			74
Currency translation			(93)
Balance, June 30, 2018	3,479		3,479
2014 Restructuring
Restructuring Reserve [Roll Forward]
Restructuring expense	0	0	0	0
Test
Restructuring Reserve [Roll Forward]
Restructuring expense	739	0	1,340	0
Test | 2017 Restructuring Plan
Restructuring Reserve [Roll Forward]
Balance, September 30, 2017			2,899
Restructuring expense			1,340
Payments			(1,451)
Other adjustments			74
Currency translation			0
Balance, June 30, 2018	2,862		2,862
Test | 2014 Restructuring
Restructuring Reserve [Roll Forward]
Balance, September 30, 2017			734
Restructuring expense			0
Payments			(202)
Other adjustments			0
Currency translation			(98)
Balance, June 30, 2018	434		434
Sensors
Restructuring Reserve [Roll Forward]
Restructuring expense	(4)	$ 92	3	$ 1,036
Sensors | 2017 Restructuring Plan
Restructuring Reserve [Roll Forward]
Balance, September 30, 2017			120
Restructuring expense			3
Payments			(92)
Other adjustments			0
Currency translation			0
Balance, June 30, 2018	31		31
Sensors | 2016 Restructuring
Restructuring Reserve [Roll Forward]
Balance, September 30, 2017			209
Restructuring expense			0
Payments			(62)
Other adjustments			0
Currency translation			5
Balance, June 30, 2018	$ 152		$ 152