Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		3 Months Ended
		Dec. 30, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income		$ 41,901	$ 30,408
Other comprehensive income (loss):
Translation adjustment, net of taxes	[1],[2]	92	(5,495)
Changes in unrealized losses on available-for-sale securities, net of taxes	[1],[3]	(7)	(3,334)
Defined benefit pension plans, net of taxes	[1],[4]	147	376
Other comprehensive income (loss), net of tax	[1]	232	(8,453)
Comprehensive income		42,133	21,955
Translation adjustment, tax (benefits)		0	(1,266)
Available-for-sale securities, tax expense (benefits)		(4)	(1,878)
Defined benefit plans, tax expense (benefits)		$ (46)	$ 21

[1] Reclassification adjustments were not significant during the three months ended December 30, 2017 and December 31, 2016.

[2] Tax benefits of $0 and $1,266 were provided on translation adjustments during the three months ended December 30, 2017 and December 31, 2016, respectively.

[3] Tax benefits of $4 and $1,878 were provided on changes in unrealized gains (losses) on available-for-sale securities for the three months ended December 30, 2017 and December 31, 2016

[4] Tax expenses (benefits) of $(46) and $21 were provided on changes in defined benefit pension plans for the three months ended December 30, 2017 and December 31, 2016, respectively.