Unaudited Condensed Consolidated Statement of Stockholder's Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	AOCI	(Accumulated deficit) Retained Earnings	Noncontrolling Interest [Member]
Stockholders' Equity Attributable to Noncontrolling Interest	$ 0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	730,485
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoptions of ASU 2014-09 (ASC 606 Rev Rec), ASU 2016-16, and ASU 2018-02, net of tax	8,593				$ 8,593
Beginning balance (in shares) at Dec. 31, 2017		31,320,000
Beginning balance at Dec. 31, 2017		$ 31	$ 603,137	$ (851)	128,168
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Change in unrealized gains and losses on available-for-sale investments, net of tax	(49)			(49)
Change in unrealized gains and losses on derivatives, net of tax	631			631
Net income	5,590				5,590
Stock-based compensation	8,150		8,150
Restricted stock unit withholdings (in shares)		(38,000)
Restricted stock unit withholdings	(2,271)				(2,271)
Issuance of common stock under stock-based compensation plans (in shares)		252,000
Issuance of common stock under stock-based compensation plans	4,590	$ 1	4,589
Ending balance (in shares) at Apr. 01, 2018		31,534,000
Ending balance at Apr. 01, 2018		$ 32	615,876	(269)	140,080
Beginning balance (in shares) at Dec. 31, 2017		31,320,000
Beginning balance at Dec. 31, 2017		$ 31	603,137	(851)	128,168
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	10,309
Net Income (Loss) Attributable to Noncontrolling Interest	$ (799)
Repurchase of common stock (in shares)	(200,000)
Repurchase of common stock	$ (15,000)
Restricted stock unit withholdings (in shares)	(100,000)
Ending balance (in shares) at Sep. 30, 2018		31,746,000
Ending balance at Sep. 30, 2018		$ 32	785,694	(36)	124,488
Stockholders' Equity Attributable to Noncontrolling Interest	$ 0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	755,719
Beginning balance (in shares) at Apr. 01, 2018		31,534,000
Beginning balance at Apr. 01, 2018		$ 32	615,876	(269)	140,080
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Change in unrealized gains and losses on available-for-sale investments, net of tax	53			53
Change in unrealized gains and losses on derivatives, net of tax	109			109
Net income	(5,230)				(5,230)
Stock-based compensation	8,970		8,970
Restricted stock unit withholdings (in shares)		(85,000)
Restricted stock unit withholdings	(4,897)				(4,897)
Issuance of common stock under stock-based compensation plans (in shares)		332,000
Issuance of common stock under stock-based compensation plans	1,012	$ 0	1,012
Ending balance (in shares) at Jul. 01, 2018		31,781,000
Ending balance at Jul. 01, 2018		$ 32	625,858	(107)	129,953
Stockholders' Equity Attributable to Noncontrolling Interest	0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	755,736
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Change in unrealized gains and losses on available-for-sale investments, net of tax	31			31
Change in unrealized gains and losses on derivatives, net of tax	40			40
Net income	9,949				9,949
Net Income (Loss) Attributable to Noncontrolling Interest	(799)					$ (799)
Stock-based compensation	8,612		8,612
Noncontrolling Interest, Share-based Compensation	942					942
Noncontrolling Interest, Increase from Sale of Parent Equity Interest	170,246		146,088			$ 24,158
Repurchase of common stock (in shares)		(205,000)
Repurchase of common stock	(15,000)				(15,000)
Restricted stock unit withholdings (in shares)		(6,000)
Restricted stock unit withholdings	(414)				(414)
Issuance of common stock under stock-based compensation plans (in shares)		176,000
Issuance of common stock under stock-based compensation plans	5,136		5,136
Ending balance (in shares) at Sep. 30, 2018		31,746,000
Ending balance at Sep. 30, 2018		$ 32	785,694	(36)	124,488
Stockholders' Equity Attributable to Noncontrolling Interest	24,301
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	934,479
Beginning balance (in shares) at Dec. 31, 2018		31,562,000
Beginning balance at Dec. 31, 2018	627,552	$ 32	793,585	(15)	(166,050)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Change in unrealized gains and losses on available-for-sale investments, net of tax	12			12
Change in unrealized gains and losses on derivatives, net of tax	17			17
Net income	12,843				12,843
Stock-based compensation	6,457		6,457
Repurchase of common stock (in shares)		(436,000)
Repurchase of common stock	(15,000)	$ 0			(15,000)
Restricted stock unit withholdings (in shares)		(89,000)
Restricted stock unit withholdings	(3,344)				(3,344)
Issuance of common stock under stock-based compensation plans (in shares)		430,000
Issuance of common stock under stock-based compensation plans	4,371	$ 0	4,371
Ending balance (in shares) at Mar. 31, 2019		31,467,000
Ending balance at Mar. 31, 2019	632,908	$ 32	804,413	14	(171,551)
Beginning balance (in shares) at Dec. 31, 2018		31,562,000
Beginning balance at Dec. 31, 2018	627,552	$ 32	793,585	(15)	(166,050)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	26,211
Net Income (Loss) Attributable to Noncontrolling Interest	$ 0
Repurchase of common stock (in shares)	(1,700,000)
Repurchase of common stock	$ (53,900)
Restricted stock unit withholdings (in shares)	(200,000)
Ending balance (in shares) at Sep. 29, 2019		30,581,000
Ending balance at Sep. 29, 2019	$ 622,138	$ 31	821,966	(18)	(199,841)
Beginning balance (in shares) at Mar. 31, 2019		31,467,000
Beginning balance at Mar. 31, 2019	632,908	$ 32	804,413	14	(171,551)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Change in unrealized gains and losses on derivatives, net of tax	(2)			(2)
Net income	839				839
Stock-based compensation	6,739		6,739
Repurchase of common stock (in shares)		(570,000)
Repurchase of common stock	(16,980)	$ (1)			(16,979)
Restricted stock unit withholdings (in shares)		(79,000)
Restricted stock unit withholdings	(2,314)				(2,314)
Issuance of common stock under stock-based compensation plans (in shares)		292,000
Issuance of common stock under stock-based compensation plans	882	$ 0	882
Ending balance (in shares) at Jun. 30, 2019		31,110,000
Ending balance at Jun. 30, 2019	622,072	$ 31	812,034	12	(190,005)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Change in unrealized gains and losses on derivatives, net of tax	(30)			(30)
Net income	12,529				12,529
Net Income (Loss) Attributable to Noncontrolling Interest	0
Stock-based compensation	6,986		6,986
Repurchase of common stock (in shares)		(679,000)
Repurchase of common stock	(21,966)	$ (1)			(21,965)
Restricted stock unit withholdings (in shares)		(12,000)
Restricted stock unit withholdings	(400)				(400)
Issuance of common stock under stock-based compensation plans (in shares)		162,000
Issuance of common stock under stock-based compensation plans	2,947	$ 1	2,946
Ending balance (in shares) at Sep. 29, 2019		30,581,000
Ending balance at Sep. 29, 2019	$ 622,138	$ 31	$ 821,966	$ (18)	$ (199,841)