Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 27, 2015	Sep. 27, 2015	Sep. 28, 2014	Sep. 29, 2013
Income (loss) before income taxes:
United States		$ 118,822	$ 118,900	$ 60,547
Foreign		(38,501)	25,443	(48,015)
Total income before income taxes		80,321	144,343	12,532
Current:
Federal		23,836	26,503	11,155
State		5,072	7,551	2,705
Foreign		3,773	1,759	11,646
Total current income tax expense		32,681	35,813	25,506
Deferred:
Federal		7,218	5,957	(2,965)
State		2,335	434	(637)
Foreign		(1,141)	(6,536)	(7,866)
Total deferred income tax expense (benefit)		8,412	(145)	(11,468)
Total income tax expense		$ 41,093	$ 35,668	$ 14,038
Reconciliation of effective income tax rate
Tax at federal statutory rate (as a percent)		35.00%	35.00%	35.00%
State taxes, net of federal benefit (as a percent)		5.00%	3.40%	10.50%
R&E credits (as a percent)		(3.80%)	(0.60%)	(52.80%)
Domestic production deduction (as a percent)		(0.80%)	(0.70%)	(6.60%)
Tax differential on foreign earnings (as a percent)		(2.50%)	(5.50%)	(34.00%)
Corrections of prior-year errors (as a percent)				26.00%
Goodwill and contingent consideration (as a percent)		12.00%	(8.20%)	90.00%
Stock compensation (as a percent)		0.50%	0.20%	3.50%
Valuation allowance (as a percent)		5.70%	0.30%	39.50%
Other (as a percent)		0.10%	0.80%	0.90%
Total income tax expense (as a percent)		51.20%	24.70%	112.00%
Impairment charge	$ 60,800	$ 60,800
Effective income tax rate excluding adjustments (as a percent)		32.30%	36.20%
Tax benefit attributable to operating income		$ 1,200