Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 25, 2016	Jun. 27, 2015
Cash flows provided by operating activities:
Net income	$ 33,653	$ 43,675
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	24,473	20,455
Impairment of assets	37
Loss on disposal of property, plant and equipment	511	339
Bad debt recovery	(55)	(49)
Stock-based compensation expense	5,741	3,632
Excess tax benefit from stock-based compensation arrangements	(5,840)	(12,847)
Deferred income taxes	1,375	1,862
Changes in operating assets and liabilities:
Accounts receivable	(17,655)	(15,666)
Inventories	(4,783)	(5,812)
Prepaid expenses, income tax receivable and other assets	12,394	33,201
Accounts payable	(1,995)	11,570
Accrued expenses and other current liabilities	6,967	(2,430)
Other liabilities	(6,504)	424
Net cash provided by operating activities	48,319	78,354
Cash flows used in investing activities:
Purchases of property, plant and equipment	(25,954)	(38,880)
Cash paid for acquisition of intangible assets		(100)
Decrease in restricted cash	56	57
Net cash used in investing activities	(25,898)	(38,923)
Cash flows (used in) provided by financing activities:
Repurchase of Class A Common Stock	(124,675)	(22,782)
Proceeds from exercise of stock options	29,521	40,332
Cash paid on note payable	(58)	(54)
Excess tax benefit from stock-based compensation arrangements	5,840	12,847
Net proceeds from sale of investment shares	338	807
Net cash (used in) provided by financing activities	(89,034)	31,150
Change in cash and cash equivalents	(66,613)	70,581
Cash and cash equivalents at beginning of year	94,193	76,402
Cash and cash equivalents at end of period	27,580	146,983
Supplemental disclosure of cash flow information:
Income taxes paid	8,655	9,738
Income taxes refunded	12,000	17,226
Increase (Decrease) in accounts payable for purchase of property, plant and equipment	$ 870	$ (1,134)