Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018
Operating Activities
Net income	$ 5,398	$ 26,405
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation of property and equipment	4,137	3,704
Amortization of other intangible assets and other assets	10,320	6,427
Amortization of debt discount and debt issuance costs	3,321	3,169
Stock-based compensation expense	12,584	12,192
Deferred income taxes	(3,530)	(4,780)
Changes in operating assets and liabilities:
Accounts receivable	3,323	(3,307)
Inventories	4,488	(3,368)
Prepaid expenses and other assets	6,410	(17,169)
Accounts payable	714	13,030
Other current liabilities and income taxes	(15,996)	(9,643)
Deferred income, deferred revenue and returns liability	1,477	(2,599)
Other non-current liabilities	(631)	(1,849)
Net cash provided by operating activities	32,015	22,212
Investing Activities
Purchases of available-for-sale investments	(63,577)	(52,821)
Sales and maturities of available-for-sale investments	99,068	128,975
Purchases of property and equipment	(3,874)	(4,102)
Purchases of other assets	(414)	(4,698)
Net cash provided by investing activities	31,203	67,354
Financing Activities
Repurchases of common stock	(15,004)
Payment of taxes withheld for vested stock awards	(14,113)	(17,871)
Proceeds from the issuance of common stock		1,211
Net cash used in financing activities	(29,117)	(16,660)
Increase in cash and cash equivalents	34,101	72,906
Cash and cash equivalents at beginning of period	197,043	269,366
Cash and cash equivalents at end of period	$ 231,144	$ 342,272