Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Apr. 01, 2017	Mar. 26, 2016
Cash Flows from Operating Activities:
Net income	$ 29,187	$ 24,671
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation, amortization and accretion	5,005	4,499
Provision for doubtful accounts	75	996
Benefit for deferred income taxes	(1,186)	(442)
Provision for non-cash stock compensation	653	440
Changes in assets and liabilities:
Accounts receivable	(2,473)	(4,468)
Inventories	(818)	6,139
Prepaids and other current assets	144	(405)
Other assets	(191)	(1,487)
Accounts payable	(668)	(11,930)
Accrued compensation and other liabilities	8,417	5,901
Cash provided by operating activities	38,145	23,914
Cash Flows from Investing Activities:
Property, plant and equipment additions	(5,618)	(5,598)
Purchase of investments	(13,127)
Cash used in investing activities	(18,745)	(5,598)
Cash Flows from Financing Activities:
Other stock related activity	(856)	(11)
Purchase and cancellation of common stock	(11,321)	(9,986)
Cash used in financing activities	(12,177)	(9,997)
Net Increase in Cash and Cash Equivalents	7,223	8,319
Cash and Cash Equivalents, Beginning of Period	149,121	78,659
Cash and Cash Equivalents, End of Period	156,344	86,978
Supplemental Cash Flow Information
Cash paid for interest expense	61	70
Cash paid for income taxes	$ 1,046	$ 2,568