Condensed Consolidated Statement of Changes Shareholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands		Total	Cumulative Effect, Period of Adoption, Adjustment	[2]	Common Stock	Treasury Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Deficit Cumulative Effect, Period of Adoption, Adjustment	[2]	Accumulated Other Comprehensive Income (Loss)
Balance at beginning of period (in shares) at Sep. 30, 2018					47,080
Balance at beginning of period at Sep. 30, 2018		$ 122,059			$ 472	$ (2,580)	$ 457,978	$ (317,373)			$ (16,438)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		26,949						26,949
Other comprehensive (loss) income		(2,721)									(2,721)
Stock-based compensation		2,982					2,982
Issuance of common stock (in shares)					131
Issuance of common stock		(695)			$ 1		(696)
Repurchase of common stock (in shares)					(1,230)
Repurchase of common stock		(24,419)			$ (12)			(24,407)
Balance at end of period (in shares) at Dec. 28, 2018					45,981
Balance at end of period at Dec. 28, 2018		124,155			$ 461	(2,580)	460,264	(314,831)			(19,159)
Balance at beginning of period (in shares) at Sep. 30, 2018					47,080
Balance at beginning of period at Sep. 30, 2018		122,059			$ 472	(2,580)	457,978	(317,373)			(16,438)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		93,054
Other comprehensive (loss) income		(2,344)
Reclassification of stranded tax benefits											(2,333)
Balance at end of period (in shares) at Jun. 28, 2019					46,676
Balance at end of period at Jun. 28, 2019		202,518			$ 468	(2,580)	472,138	(246,393)			(21,115)
Balance at beginning of period (in shares) at Dec. 28, 2018					45,981
Balance at beginning of period at Dec. 28, 2018		124,155			$ 461	(2,580)	460,264	(314,831)			(19,159)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		29,555						29,555
Other comprehensive (loss) income		967									967
Reclassification of stranded tax benefits	[1]	0						2,333			(2,333)
Stock-based compensation		1,834					1,834
Issuance of common stock (in shares)					235
Issuance of common stock		1,986			$ 2		1,984
Repurchase of common stock		0
Balance at end of period (in shares) at Mar. 29, 2019					46,216
Balance at end of period at Mar. 29, 2019		158,497			$ 463	(2,580)	464,082	(282,943)			(20,525)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		36,550						36,550
Other comprehensive (loss) income		(590)									(590)
Stock-based compensation		4,120					4,120
Issuance of common stock (in shares)					460
Issuance of common stock		3,941			$ 5		3,936
Balance at end of period (in shares) at Jun. 28, 2019					46,676
Balance at end of period at Jun. 28, 2019		202,518			$ 468	(2,580)	472,138	(246,393)			(21,115)
Balance at beginning of period (in shares) at Sep. 30, 2019					46,955
Balance at beginning of period at Sep. 30, 2019		232,936	$ (1,053)		$ 471	(2,580)	477,139	(200,396)	$ (1,053)		(41,698)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		34,790						34,790
Other comprehensive (loss) income		5,316									5,316
Stock-based compensation		3,123					3,123
Issuance of common stock (in shares)					524
Issuance of common stock		(2,981)			$ 5		(2,986)
Balance at end of period (in shares) at Dec. 27, 2019					47,479
Balance at end of period at Dec. 27, 2019		$ 272,131			$ 476	(2,580)	477,276	(166,659)			(36,382)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible List]		us-gaap:AccountingStandardsUpdate201602Member
Balance at beginning of period (in shares) at Sep. 30, 2019					46,955
Balance at beginning of period at Sep. 30, 2019		$ 232,936	$ (1,053)		$ 471	(2,580)	477,139	(200,396)	$ (1,053)		(41,698)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		98,061
Other comprehensive (loss) income		1,781
Balance at end of period (in shares) at Jun. 26, 2020					47,176
Balance at end of period at Jun. 26, 2020		324,195			$ 474	(2,580)	484,613	(118,395)			(39,917)
Balance at beginning of period (in shares) at Dec. 27, 2019					47,479
Balance at beginning of period at Dec. 27, 2019		272,131			$ 476	(2,580)	477,276	(166,659)			(36,382)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		39,193						39,193
Other comprehensive (loss) income		(6,003)									(6,003)
Stock-based compensation		4,523					4,523
Issuance of common stock (in shares)					91
Issuance of common stock		601			$ 1		600
Repurchase of common stock (in shares)					(394)
Repurchase of common stock		(15,011)			$ (4)			(15,007)
Balance at end of period (in shares) at Mar. 27, 2020					47,176
Balance at end of period at Mar. 27, 2020		295,434			$ 473	(2,580)	482,399	(142,473)			(42,385)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		24,078						24,078
Other comprehensive (loss) income		2,468									2,468
Stock-based compensation		1,656					1,656
Issuance of common stock		559			$ 1		558
Balance at end of period (in shares) at Jun. 26, 2020					47,176
Balance at end of period at Jun. 26, 2020		$ 324,195			$ 474	$ (2,580)	$ 484,613	$ (118,395)			$ (39,917)

[1] Due to the adoption of ASU 2018-02.

[2] Due to the adoption of ASU 2016-02