Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Balance at the beginning of the year (in shares) at Oct. 01, 2016		16,660,000
Balance at the beginning of the year at Oct. 01, 2016	$ 405,260	$ 4,165	$ 154,879	$ 256,589	$ (10,373)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total comprehensive income	34,904			25,084	9,820
Conversion of tangible equity units (in shares)		939,000
Conversion of tangible equity units	0	$ 235	(235)
Settlement of capped calls (in shares)		(12,000)
Settlement of capped calls	$ 0	$ (3)	3
Exercise of stock options (in shares)	112,000	112,000
Exercise of stock options	$ 4,559	$ 28	4,531
Stock-based compensation (in shares)		69,000
Stock-based compensation	5,620	$ 17	5,603
Tax shortfall from equity compensation	(386)		(386)
Issuance for employee stock purchase plan (in shares)		25,000
Issuance for employee stock purchase plan	1,020	$ 6	1,014
Common stock purchased and retired (in shares)		(33,000)
Common stock purchased and retired	(1,785)	$ (8)	(1,777)
Dividends, $1.20 per share	(20,415)			(20,415)
Balance at the end of the year (in shares) at Sep. 30, 2017		17,760,000
Balance at the end of the year at Sep. 30, 2017	428,777	$ 4,440	163,632	261,258	(553)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total comprehensive income	$ 62,717			61,328	1,389
Settlement of capped calls (in shares)	0
Exercise of stock options (in shares)	19,000	19,000
Exercise of stock options	$ 921	$ 5	916
Stock-based compensation (in shares)		79,000
Stock-based compensation	7,243	$ 19	7,224
Issuance for employee stock purchase plan (in shares)		24,000
Issuance for employee stock purchase plan	1,071	$ 6	1,065
Common stock purchased and retired (in shares)		(26,000)
Common stock purchased and retired	(1,403)	$ (6)	(1,397)
Dividends, $1.20 per share	(21,394)			(21,394)
Balance at the end of the year (in shares) at Sep. 29, 2018		17,856,000
Balance at the end of the year at Sep. 29, 2018	477,932	$ 4,464	171,407	300,585	1,476
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total comprehensive income	23,118			43,067	(19,949)
Conversion of tangible equity units (in shares)		1,342,000
Conversion of tangible equity units	0	$ 336	(336)
Settlement of capped calls (in shares)		(223,000)
Settlement of capped calls	$ 0	$ (57)	57
Exercise of stock options (in shares)	47,000	47,000
Exercise of stock options	$ 2,279	$ 12	2,267
Stock-based compensation (in shares)		97,000
Stock-based compensation	9,430	$ 24	9,406
Issuance for employee stock purchase plan (in shares)		34,000
Issuance for employee stock purchase plan	1,156	$ 8	1,148
Common stock purchased and retired (in shares)		(29,000)
Common stock purchased and retired	(1,533)	$ (6)	(1,527)
Dividends, $1.20 per share	(22,096)			(22,096)
Balance at the end of the year (in shares) at Sep. 28, 2019		19,124,000
Balance at the end of the year at Sep. 28, 2019	$ 484,059	$ 4,781	$ 182,422	$ 315,329	$ (18,473)