Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018
Operating Activities
Net income (loss)	$ (10,631)	$ 40,685
Adjustments to reconcile net income (loss) to cash provided by operating activities:
Depreciation of property and equipment	8,447	7,643
Amortization of other intangible assets and other assets	20,476	18,366
Amortization of debt discount and debt issuance costs	6,659	6,354
Stock-based compensation expense	26,253	24,311
Deferred income taxes	24,043	(5,830)
Changes in operating assets and liabilities:
Accounts receivable	893	(16,705)
Inventories	1,118	(565)
Prepaid expenses and other assets	11,326	(1,759)
Accounts payable	5,321	2,980
Other current liabilities and income taxes	(18,101)	(17,249)
Deferred income, deferred revenue and returns liability	(1,228)	(4,193)
Other non-current liabilities	(3,222)	(3,260)
Net cash provided by operating activities	71,354	50,778
Investing Activities
Purchases of available-for-sale investments	(184,170)	(148,437)
Sales and maturities of available-for-sale investments	151,428	295,405
Purchases of property and equipment	(9,402)	(11,406)
Purchases of other assets	(2,588)	(5,893)
Acquisition of business, net of cash acquired		(239,729)
Net cash used in investing activities	(44,732)	(110,060)
Financing Activities
Repurchases of common stock	(26,716)	(3,397)
Payment of taxes withheld for vested stock awards	(14,509)	(18,408)
Proceeds from the issuance of common stock	7,109	6,585
Net cash used in financing activities	(34,116)	(15,220)
Decrease in cash and cash equivalents	(7,494)	(74,502)
Cash and cash equivalents at beginning of period	197,043	269,366
Cash and cash equivalents at end of period	$ 189,549	$ 194,864