CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (unaudited) - USD ($) shares in Thousands, $ in Thousands	Total		Common stock	Additional Paid-in capital	Accumulated deficit	Accumulated other comprehensive loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting method transition adjustment	$ 27,401	[1]			$ 27,401
Beginning balances (in shares) at Dec. 30, 2017			123,895
Beginning balances at Dec. 30, 2017	217,693		$ 1,239	$ 695,768	(477,862)	$ (1,452)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	(26,175)				(26,175)
Unrealized gain related to marketable securities, net of tax	2					2
Recognized gain on redemption of marketable securities, previously unrealized	(1)					(1)
Translation adjustments, net of tax	(540)					(540)
Common stock issued in connection with the exercise of stock options, ESPP and vested RSUs (in shares)			1,718
Common stock issued in connection with the exercise of stock options, ESPP and vested RSUs, net of tax	5,040		$ 17	5,023
Stock-based compensation related to stock options, ESPP and RSUs	7,200			7,200
Ending balances (in shares) at Jun. 30, 2018			125,613
Ending balances at Jun. 30, 2018	230,620		$ 1,256	707,991	(476,636)	(1,991)
Beginning balances (in shares) at Mar. 31, 2018			124,311
Beginning balances at Mar. 31, 2018	245,672		$ 1,243	701,713	(456,413)	(871)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	(20,223)				(20,223)
Unrealized gain related to marketable securities, net of tax	9					9
Translation adjustments, net of tax	(1,129)					(1,129)
Common stock issued in connection with the exercise of stock options, ESPP and vested RSUs (in shares)			1,302
Common stock issued in connection with the exercise of stock options, ESPP and vested RSUs, net of tax	3,891		$ 13	3,878
Stock-based compensation related to stock options, ESPP and RSUs	2,400			2,400
Ending balances (in shares) at Jun. 30, 2018			125,613
Ending balances at Jun. 30, 2018	$ 230,620		$ 1,256	707,991	(476,636)	(1,991)
Beginning balances (in shares) at Dec. 29, 2018	129,728		129,728
Beginning balances at Dec. 29, 2018	$ 258,457		$ 1,297	736,274	(476,783)	(2,331)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	15,967				15,967
Unrealized gain related to marketable securities, net of tax	42					42
Recognized gain on redemption of marketable securities, previously unrealized	(53)					(53)
Translation adjustments, net of tax	86					86
Common stock issued in connection with the exercise of stock options, ESPP and vested RSUs (in shares)			2,808
Common stock issued in connection with the exercise of stock options, ESPP and vested RSUs, net of tax	13,023		$ 28	12,995
Stock-based compensation related to stock options, ESPP and RSUs	$ 7,655			7,655
Ending balances (in shares) at Jun. 29, 2019	132,536		132,536
Ending balances at Jun. 29, 2019	$ 295,177		$ 1,325	756,924	(460,816)	(2,256)
Beginning balances (in shares) at Mar. 30, 2019			131,905
Beginning balances at Mar. 30, 2019	281,155		$ 1,319	751,506	(469,375)	(2,295)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	8,559				8,559
Translation adjustments, net of tax	39					39
Common stock issued in connection with the exercise of stock options, ESPP and vested RSUs (in shares)			631
Common stock issued in connection with the exercise of stock options, ESPP and vested RSUs, net of tax	1,455		$ 6	1,449
Stock-based compensation related to stock options, ESPP and RSUs	$ 3,969			3,969
Ending balances (in shares) at Jun. 29, 2019	132,536		132,536
Ending balances at Jun. 29, 2019	$ 295,177		$ 1,325	$ 756,924	$ (460,816)	$ (2,256)

[1] As of the beginning of fiscal 2018, we adopted ASC 606, "Revenue from Contracts With Customers," using the modified retrospective transition method. As a result of this adoption, we recorded a cumulative-effect adjustment to Accumulated Deficit, as shown in the table above.