Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Apr. 03, 2016	Apr. 05, 2015
Cash flows from operating activities:
Net income	$ 14,885	$ 20,502
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation expense	6,804	6,946
Depreciation of property, plant, and equipment	2,757	2,346
Amortization of intangible assets	1,045	1,093
Amortization of discounts or premiums on investments	125	203
Realized (gain) loss on sale of investments	13	(29)
Revaluation of contingent consideration	(263)	0
Change in deferred income taxes	(2,064)	(1,251)
Accounts receivable	(1,025)	(8,005)
Inventories	2,646	(15,046)
Accounts payable	2,216	(5,013)
Accrued expenses	(3,353)	(7,210)
Accrued income taxes	467	3,580
Other	3,327	5,314
Net cash provided by operating activities	27,580	3,430
Cash flows from investing activities:
Purchases of investments	(219,616)	(157,083)
Maturities and sales of investments	223,334	130,476
Purchases of property, plant, and equipment	(2,237)	(4,264)
Net cash provided by (used in) investing activities	1,481	(30,871)
Cash flows from financing activities:
Issuance of common stock under stock plans	3,440	9,666
Payment of dividends	(5,950)	0
Net cash provided by (used in) used in financing activities	(2,510)	9,666
Effect of foreign exchange rate changes on cash and cash equivalents	1,388	(1,872)
Net change in cash and cash equivalents	27,939	(19,647)
Cash and cash equivalents at beginning of period	51,975	55,694
Cash and cash equivalents at end of period	79,914	36,047
Non-cash items related to discontinued operations:
Capital expenditures	0	311
Stock-based compensation expense	0	283
Depreciation and amortization expense	$ 0	$ 281