Income Taxes Income Tax Rate Reconciliation (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 28, 2015	Mar. 29, 2014
Income Taxes [Abstract]
Expected federal income tax expense at statutory rate	$ 6,875	$ 6,494
Effect of foreign source income	(3,021)	(2,746)
Valuation allowance	449	0
Other items, net	367	495
Income tax expense	$ 4,670us-gaap_IncomeTaxExpenseBenefit	$ 4,243us-gaap_IncomeTaxExpenseBenefit

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to increase (decrease) in the valuation allowance for deferred tax assets.

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The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations.

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