Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjustment Additional Paid-In Capital	Cumulative Effect, Period of Adoption, Adjustment Retained Earnings	Cumulative Effect, Period of Adoption, Adjustment Accumulated Other Comprehensive Income (Loss)
Balance at the beginning of the year (in shares) at Sep. 30, 2017		17,760,000
Balance at the beginning of the year at Sep. 30, 2017	$ 428,777	$ 4,440	$ 163,632	$ 261,258	$ (553)	$ 0	$ (33)	$ (607)	$ 640
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total comprehensive income (loss)	$ 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	(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	$ (6,227)		$ (6,227)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total comprehensive income (loss)	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	(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)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total comprehensive income (loss)	$ (258,559)			(272,051)	13,492
Exercise of stock options (in shares)	1,000	1,000
Exercise of stock options	$ 41		41
Stock-based compensation (in shares)		123,000
Stock-based compensation	7,214	$ 31	7,183
Issuance for employee stock purchase plan (in shares)		53,000
Issuance for employee stock purchase plan	1,146	$ 13	1,133
Common stock purchased and retired (in shares)		(37,000)
Common stock purchased and retired	(1,208)	$ (9)	(1,199)
Dividends	(11,510)			(11,510)
Balance at the end of the year (in shares) at Oct. 03, 2020		19,264,000
Balance at the end of the year at Oct. 03, 2020	$ 221,183	$ 4,816	$ 189,580	$ 31,768	$ (4,981)