Significant Accounting Policies (Schedule of Acquired Intangible Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets beginning balance	$ 336,922	$ 353,419	$ 440,192
Acquisitions	35,905	18,172	(5,307)
Amortization	(46,095)	(47,608)	(49,368)
Foreign currency translation	4,305	9,733	(35,517)
Acquired intangible assets ending balance	$ 332,920	336,922	353,419
Weighted Average Amortization Period (years)	8 years 3 months 19 days
Excluding Investment in AWE Management Ltd
Acquired Finite Lived Intangible Assets [Line Items]
Amortization	$ (44,212)	(44,402)	(45,949)
Customer Relationships, Contracts, and Backlog
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets beginning balance	307,637	329,341	408,041
Acquisitions	29,803	7,286	(4,315)
Foreign currency translation	3,707	9,605	(34,418)
Acquired intangible assets ending balance	$ 301,468	307,637	329,341
Weighted Average Amortization Period (years)	7 years 10 months 24 days
Customer Relationships, Contracts, and Backlog | Excluding Investment in AWE Management Ltd
Acquired Finite Lived Intangible Assets [Line Items]
Amortization	$ (39,679)	(38,595)	(39,967)
Developed Technology
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets beginning balance	14,311	15,845	17,378
Acquisitions	1,685
Acquired intangible assets ending balance	$ 14,462	14,311	15,845
Weighted Average Amortization Period (years)	7 years 8 months 12 days
Developed Technology | Excluding Investment in AWE Management Ltd
Acquired Finite Lived Intangible Assets [Line Items]
Amortization	$ (1,534)	(1,534)	(1,533)
Trade Names
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets beginning balance	4,786	7,599	14,148
Acquisitions	4,417	859	(1,292)
Foreign currency translation	45	147	(1,085)
Acquired intangible assets ending balance	$ 6,699	4,786	7,599
Weighted Average Amortization Period (years)	4 years 4 months 24 days
Trade Names | Excluding Investment in AWE Management Ltd
Acquired Finite Lived Intangible Assets [Line Items]
Amortization	$ (2,549)	(3,819)	(4,172)
Patents
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets beginning balance	10,027
Acquisitions		10,027
Foreign currency translation	553
Acquired intangible assets ending balance	$ 10,180	10,027
Weighted Average Amortization Period (years)	24 years
Patents | Excluding Investment in AWE Management Ltd
Acquired Finite Lived Intangible Assets [Line Items]
Amortization	$ (400)
Other
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets beginning balance	161	634	625
Acquisitions			300
Foreign currency translation		(19)	(14)
Acquired intangible assets ending balance	$ 111	161	634
Weighted Average Amortization Period (years)	2 years 2 months 13 days
Other | Excluding Investment in AWE Management Ltd
Acquired Finite Lived Intangible Assets [Line Items]
Amortization	$ (50)	$ (454)	$ (277)