Income Taxes - Summary (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2019	Sep. 30, 2018	Oct. 01, 2017
Income before income taxes:
United States	$ 185,535	$ 180,034	$ 166,074
Foreign	(10,399)	(5,472)	5,687
Total income before income taxes	175,136	174,562	171,761
Current:
Federal	30,051	46,840	45,604
State	8,923	9,228	8,860
Foreign	15,016	10,897	9,337
Total current income tax expense	53,990	66,965	63,801
Deferred:
Federal	(9,108)	(22,072)	(4,251)
State	(1,195)	(1,471)	(945)
Foreign	(27,312)	(5,817)	(4,761)
Total deferred income tax expense	(37,615)	(29,360)	(9,957)
Total income tax expense	$ 16,375	$ 37,605	$ 53,844
Reconciliation of effective income tax rate
Tax at federal statutory rate	21.00%	24.50%	35.00%
State taxes, net of federal benefit	3.40%	4.20%	3.40%
Research and Development (R&D) credits	(4.70%)	(1.40%)	(1.80%)
Domestic production deduction	0.00%	(0.20%)	(0.70%)
Tax differential on foreign earnings	1.00%	0.50%	0.00%
Non-taxable foreign interest income	(1.70%)	(2.00%)	(2.90%)
Goodwill	0.90%	1.70%	0.00%
Stock compensation	(2.40%)	(2.70%)	(2.80%)
Valuation allowance	(13.50%)	(0.50%)	(0.50%)
Change in uncertain tax positions	2.40%	1.90%	1.80%
Revaluation of deferred taxes	(0.014)	(0.084)	0
Deferred tax adjustments	(0.40%)	2.10%	0.00%
Transition tax on foreign earnings	0.014	0	0
Other	3.30%	1.80%	(0.20%)
Total income tax expense	9.30%	21.50%	31.30%