Derivative Instruments and Hedging Activities (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017	Sep. 30, 2017
Derivative [Line Items]
Gross notional amount of foreign exchange derivatives outstanding	$ 43,200		$ 43,200		$ 29,136
Net notional amount of foreign exchange derivatives	32,226		32,226		24,093
Recognized in earnings as a result of the ineffectiveness of cash flow hedges	5	$ 0	10	$ 7
Gain (loss) projected to be reclassified from Accumulated Other Comprehensive Income into earnings, within twelve months			$ 552
Maximum remaining maturity of any forward or optional contract derivatives (in years)			1 year 7 months 15 days
Cash flow derivatives
Derivative [Line Items]
Foreign currency exchange contract asset, net value	617		$ 617		(478)
Foreign currency exchange contract, net asset market value	731		731		73
Foreign currency exchange contract, net liability market value	114		114		551
Interest rate swaps
Derivative [Line Items]
Gain (loss) projected to be reclassified from Accumulated Other Comprehensive Income into earnings, within twelve months			2,821
Notional amount	$ 255,000		$ 255,000
Fixed interest rate	1.256%		1.256%
Interest rate swaps	$ 7,354		$ 7,354		3,499
Foreign exchange balance sheet derivative contracts
Derivative [Line Items]
Gross notional amount of foreign exchange derivatives outstanding	77,464		77,464		52,208
Net notional amount of foreign exchange derivatives	27,171		27,171		14,762
Foreign currency exchange contract asset, net value	$ 246		$ 246		$ 77