Income Taxes - Acquisition and integration expenses information (Details) - USD ($) $ in Thousands	3 Months Ended
	Jan. 01, 2017	Dec. 27, 2015
Effective tax rate (as a percent)	28.00%	25.70%
Income tax benefit	$ 10,358	$ 8,030
R&D Credits		$ 2,000
Effective income tax rate excluding R&D credits (as a percent)	32.80%	32.10%
Period of projected cumulative pre-tax losses in certain foreign jurisdictions	36 months
Foreign
Loss carry-forwards, valuation allowance	$ 23,700
Accounting Standards Update 2016-09
Income tax benefit	$ (1,800)