CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Treasury Stock	Accumulated Deficit	Accumulated Other Comprehensive Loss
Balance, beginning of period (in shares) at Sep. 28, 2019		109,623,417		1,020,775
Balance, beginning of period at Sep. 28, 2019	$ 280,928	$ 110	$ 502,757	$ (13,498)	$ (208,377)	$ (64)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock pursuant to equity incentive plans (in shares)		1,561,696
Issuance of common stock pursuant to equity incentive plans	7,969	$ 1	7,968
Purchase of common stock (in shares)				(227,241)
Repurchase of common stock	(2,926)			$ (2,926)
Repurchase of common stock related to shares withheld for tax in connection with vesting of restricted stock unit awards ("RSUs") (in shares)				(144,908)
Repurchase of common stock related to shares withheld for tax in connection with vesting of restricted stock unit awards ("RSUs")	(2,152)			$ (2,152)
Stock-based compensation expense	13,204		13,204
Net income (loss)	70,775				70,775
Change in foreign currency translation adjustment	(519)					(519)
Balance, end of period (in shares) at Dec. 28, 2019		111,185,113		1,392,924
Balance, ending of period at Dec. 28, 2019	367,279	$ 111	523,929	$ (18,576)	(137,602)	(583)
Balance, beginning of period (in shares) at Sep. 28, 2019		109,623,417		1,020,775
Balance, beginning of period at Sep. 28, 2019	280,928	$ 110	502,757	$ (13,498)	(208,377)	(64)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	18,454
Change in foreign currency translation adjustment	(950)
Balance, end of period (in shares) at Mar. 28, 2020		112,733,727		3,884,652
Balance, ending of period at Mar. 28, 2020	299,804	$ 113	541,937	$ (51,310)	(189,922)	(1,014)
Balance, beginning of period (in shares) at Dec. 28, 2019		111,185,113		1,392,924
Balance, beginning of period at Dec. 28, 2019	367,279	$ 111	523,929	$ (18,576)	(137,602)	(583)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock pursuant to equity incentive plans (in shares)		1,548,614
Issuance of common stock pursuant to equity incentive plans	4,616	$ 2	4,614
Purchase of common stock (in shares)				(2,309,604)
Repurchase of common stock	(30,290)			$ (30,290)
Repurchase of common stock related to shares withheld for tax in connection with vesting of restricted stock unit awards ("RSUs") (in shares)				(182,124)
Repurchase of common stock related to shares withheld for tax in connection with vesting of restricted stock unit awards ("RSUs")	(2,444)			$ (2,444)
Stock-based compensation expense	13,394		13,394
Net income (loss)	(52,320)				(52,320)
Change in foreign currency translation adjustment	(431)					(431)
Balance, end of period (in shares) at Mar. 28, 2020		112,733,727		3,884,652
Balance, ending of period at Mar. 28, 2020	299,804	$ 113	541,937	$ (51,310)	(189,922)	(1,014)
Balance, beginning of period (in shares) at Oct. 03, 2020		113,915,233		1,571,138
Balance, beginning of period at Oct. 03, 2020	297,839	$ 114	548,993	$ (20,886)	(228,492)	(1,890)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock pursuant to equity incentive plans (in shares)		7,075,338
Issuance of common stock pursuant to equity incentive plans	69,505	$ 7	69,498
Repurchase of common stock related to shares withheld for tax in connection with vesting of restricted stock unit awards ("RSUs") (in shares)				(307,980)
Repurchase of common stock related to shares withheld for tax in connection with vesting of restricted stock unit awards ("RSUs")	(5,118)			$ (5,118)
Stock-based compensation expense	14,844		14,844
Net income (loss)	132,292				132,292
Change in foreign currency translation adjustment	847					847
Balance, end of period (in shares) at Jan. 02, 2021		120,990,571		1,879,118
Balance, ending of period at Jan. 02, 2021	510,209	$ 121	633,335	$ (26,004)	(96,200)	(1,043)
Balance, beginning of period (in shares) at Oct. 03, 2020		113,915,233		1,571,138
Balance, beginning of period at Oct. 03, 2020	$ 297,839	$ 114	548,993	$ (20,886)	(228,492)	(1,890)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock pursuant to equity incentive plans (in shares)	10,829,628
Retirement of treasury stock (in shares)	1,017,308
Purchase of common stock (in shares)	(19,547)
Net income (loss)	$ 149,513
Change in foreign currency translation adjustment	1,046
Balance, end of period (in shares) at Apr. 03, 2021		125,716,622		1,268,563
Balance, ending of period at Apr. 03, 2021	579,268	$ 126	684,988	$ (26,023)	(78,979)	(844)
Balance, beginning of period (in shares) at Jan. 02, 2021		120,990,571		1,879,118
Balance, beginning of period at Jan. 02, 2021	510,209	$ 121	633,335	$ (26,004)	(96,200)	(1,043)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock pursuant to equity incentive plans (in shares)		5,743,359
Issuance of common stock pursuant to equity incentive plans	49,661	$ 6	49,655
Retirement of treasury stock (in shares)		1,017,308		1,017,308
Retirement of treasury stock	0	$ (1)	(14,365)	$ 14,366
Purchase of common stock (in shares)				(19,547)
Repurchase of common stock	(682)			$ (682)
Repurchase of common stock related to shares withheld for tax in connection with vesting of restricted stock unit awards ("RSUs") (in shares)				(387,206)
Repurchase of common stock related to shares withheld for tax in connection with vesting of restricted stock unit awards ("RSUs")	(13,703)			$ (13,703)
Stock-based compensation expense	16,363		16,363
Net income (loss)	17,221				17,221
Change in foreign currency translation adjustment	199					199
Balance, end of period (in shares) at Apr. 03, 2021		125,716,622		1,268,563
Balance, ending of period at Apr. 03, 2021	$ 579,268	$ 126	$ 684,988	$ (26,023)	$ (78,979)	$ (844)