Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 27, 2014	Dec. 28, 2013	Dec. 29, 2012
Net income	$ 138,809us-gaap_NetIncomeLoss	$ 146,009us-gaap_NetIncomeLoss	$ 129,781us-gaap_NetIncomeLoss
Other comprehensive (loss) income:
Unrealized holding (losses) gains on available-for-sale investments, net of tax benefit (expense) of $76, $365 and ($221)	(139)	(664)	400
Foreign currency translation (losses) gains	(1,034)	(718)	243
Other comprehensive (loss) income	(1,173)	(1,382)	643
Comprehensive income	$ 137,636us-gaap_ComprehensiveIncomeNetOfTax	$ 144,627us-gaap_ComprehensiveIncomeNetOfTax	$ 130,424us-gaap_ComprehensiveIncomeNetOfTax

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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