Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 28, 2014	Jun. 29, 2013
Cash flows provided by operating activities:
Net income	$ 33,743	$ 26,627
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	15,391	11,463
Loss on disposal of property, plant and equipment	71	190
Bad debt expense	120	28
Stock-based compensation expense	3,937	3,782
Excess tax benefit from stock-based compensation arrangements	(8,131)	(4,825)
Deferred income tax	(101)	(208)
Changes in operating assets and liabilities:
Accounts receivable	(15,881)	(12,029)
Inventories	(7,935)	(7,073)
Prepaid expenses and other assets	(3,500)	(7,910)
Accounts payable	2,724	3,583
Accrued expenses and other current liabilities	17,766	4,487
Other liabilities	116	(127)
Net cash provided by operating activities	38,320	17,988
Cash flows used in investing activities:
Purchases of property, plant and equipment	(88,451)	(45,563)
Decrease in restricted cash	55	62
Net cash used in investing activities	(88,396)	(45,501)
Cash flows provided by (used in) financing activities:
Repurchase of Class A Common Stock		(29,586)
Proceeds from exercise of stock options	23,126	2,216
Cash paid on note payable and capital lease	(53)	(62)
Excess tax benefit from stock-based compensation arrangements	8,131	4,825
Net proceeds from sale of investment shares	630	531
Net cash provided by (used in) financing activities	31,834	(22,076)
Change in cash and cash equivalents	(18,242)	(49,589)
Cash and cash equivalents at beginning of period	49,524	74,463
Cash and cash equivalents at end of period	31,282	24,874
Supplemental disclosure of cash flow information:
Income taxes paid	7,605	10,602
Acquisition of property and equipment under capital lease		252
Increase in accounts payable for purchase of property, plant and equipment	$ 7,950