Goodwill and Intangible Assets (Amortization of Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of acquired intangible assets	$ 7,850	$ 7,973	$ 23,566	$ 23,986
Cost of license and subscription revenue	6,798	6,517	20,029	19,294
Total amortization expense	$ 14,648	$ 14,490	$ 43,595	$ 43,280