Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017
Operating Activities
Net Income	$ 40,685	$ 31,995
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation of property and equipment	7,643	7,308
Amortization of other intangible assets and other assets	18,366	13,571
Amortization of debt discount and debt issuance costs	6,354	3,907
Stock-based compensation expense	24,311	21,652
Deferred income taxes	(5,830)	(6,242)
Changes in operating assets and liabilities:
Accounts receivable	(16,705)	(887)
Inventories	(565)	(7,737)
Prepaid expenses and other assets	(1,759)	12,539
Accounts payable	2,980	2,363
Other current liabilities and income taxes	(17,249)	14
Deferred income, deferred revenue and returns liability	(4,193)	3,251
Other non-current liabilities	(3,260)	(1,169)
Net cash provided by operating activities	50,778	80,565
Investing Activities
Purchases of available-for-sale investments	(148,437)	(389,234)
Sales and maturities of available-for-sale investments	295,405	92,307
Purchases of property and equipment	(11,406)	(8,390)
Purchases of other assets	(5,893)	(1,784)
Acquisitions of business, net of cash acquired	(239,729)	(13,658)
Net cash used in investing activities	(110,060)	(320,759)
Financing Activities
Proceeds from issuance of long-term debt, net		389,468
Payments on debt		(72,500)
Repurchases of common stock	(3,397)
Payment of taxes withheld for vested stock awards	(18,408)	(14,101)
Proceeds from the issuance of common stock	6,585	6,836
Net cash provided by (used in) financing activities	(15,220)	309,703
Increase (decrease) in cash and cash equivalents	(74,502)	69,509
Cash and cash equivalents at beginning of period	269,366	141,106
Cash and cash equivalents at end of period	$ 194,864	$ 210,615