Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 27, 2015	Jun. 28, 2014
Cash flows provided by operating activities:
Net Income	$ 43,675	$ 33,743
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	20,455	15,391
Loss on disposal of property, plant and equipment	339	71
Bad debt (recovery) expense	(49)	120
Stock-based compensation expense	3,632	3,937
Excess tax benefit from stock-based compensation arrangements	(12,847)	(8,131)
Deferred income taxes	1,862	(101)
Changes in operating assets and liabilities:
Accounts receivable	(15,666)	(15,881)
Inventories	(5,812)	(7,935)
Prepaid expenses, income tax receivable and other assets	33,201	(3,500)
Accounts payable	11,570	2,724
Accrued expenses and other current liabilities	(2,430)	17,766
Other liabilities	424	116
Net cash provided by operating activities	78,354	38,320
Cash flows used in investing activities:
Purchases of property, plant and equipment	(38,880)	(88,451)
Cash paid for other intangible assets	(100)
Decrease in restricted cash	57	55
Net cash used in investing activities	(38,923)	(88,396)
Cash flows provided by financing activities:
Repurchase of Class A Common Stock	(22,782)
Proceeds from exercise of stock options	40,332	23,126
Cash paid on note payable	(54)	(53)
Excess tax benefit from stock-based compensation arrangements	12,847	8,131
Net proceeds from sale of investment shares	807	630
Net cash provided by financing activities	31,150	31,834
Change in cash and cash equivalents	70,581	(18,242)
Cash and cash equivalents at beginning of year	76,402	49,524
Cash and cash equivalents at end of period	146,983	31,282
Supplemental disclosure of cash flow information:
Income taxes paid	9,738	7,605
(Decrease) increase in accounts payable for purchase of property, plant and equipment	$ (1,134)	$ 7,950