Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Apr. 01, 2018
Cash flows from operating activities:
Net income	$ 12,843	$ 5,590
Net loss from discontinued operations	0	(4,572)
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	5,028	5,040
Purchase premium amortization/discount accretion on investments, net	(141)	(107)
Stock-based compensation	6,458	6,864
Charges related to long-term investments	0	1,400
Deferred income taxes	1,148	870
Changes in assets and liabilities
Accounts receivable	41,136	45,561
Inventories	7,748	(1,546)
Prepaid expenses and other assets	453	(2,620)
Accounts payable	(68,431)	(15,029)
Accrued employee compensation	(13,214)	(2,720)
Other accrued liabilities	(31,371)	(19,214)
Deferred revenue	1,733	(31)
Income taxes payable	(583)	3,397
Net cash provided by (used in) continuing operating activities	(37,193)	22,883
Net cash provided by discontinued operating activities	0	34,113
Net cash provided by (used in) operating activities	(37,193)	56,996
Cash flows from investing activities:
Purchases of short-term investments	(146)	(35,167)
Proceeds from maturities of short-term investments	47,145	34,907
Purchases of property and equipment	(5,958)	(2,774)
Purchases of long-term investments	(5,200)	0
Net cash provided by (used in) continuing investing activities	35,841	(3,034)
Net cash used in discontinued investing activities	0	(410)
Net cash provided by (used in) investing activities	35,841	(3,444)
Cash flows from financing activities:
Repurchases of common stock	(15,000)	0
Restricted stock unit withholdings	(3,344)	(2,271)
Proceeds from exercise of stock options	2,026	1,912
Proceeds from issuance of common stock under employee stock purchase plan	2,303	2,732
Net cash provided by (used in)continuing financing activities	(14,015)	2,373
Net cash provided by (used in) discontinued financing activities	0	0
Net cash provided by (used in) in financing activities	(14,015)	2,373
Net increase (decrease) in cash and cash equivalents	(15,367)	55,925
Cash and cash equivalents, at beginning of period	201,047	202,870
Cash and cash equivalents, at end of period	185,680	258,795
Non-cash investing and financing activities:
Additions to property and equipment included in accounts payable and other accrued liabilities	$ 2,550	$ 598