Shareholders' Equity and Accumulated Other Comprehensive Income - Changes in Shareholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2016	Oct. 02, 2015	Sep. 30, 2016	Oct. 02, 2015
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			$ 543,077	$ 517,665
Comprehensive income	$ 20,848	$ 17,764	50,453	52,703
Dividends declared			(14,640)	(14,686)
Employee stock plans and related tax benefit			7,094	4,024
Purchase of treasury shares			(8,989)	(8,957)
Share-based compensation expense	1,100	$ 1,300	4,711	5,304
Ending Balance	$ 579,362		579,362
Temporary Equity, Carrying Amount, Period Increase (Decrease)			$ (2,344)	$ 0

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Amount of paid and unpaid cash, stock, and paid-in-kind (PIK) dividends declared, for example, but not limited to, common and preferred stock.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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The total cash inflow associated with the amount received from holders to acquire the entity's shares under incentive and share awards, including stock option exercises. This item inherently excludes any excess tax benefit, which the entity may have realized and reported separately.

+ References

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- Definition

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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Change in the value of each type or class of stock classified as temporary equity during the period. The redemption requirement does not constitute an unconditional obligation that will be settled in a variable number of shares constituting a monetary value predominantly indexed to (a) a fixed monetary amount known at inception, (b) an amount inversely correlated with the residual value of the entity, or (c) an amount determined by reference to something other than the fair value of issuer's stock. Does not include mandatorily redeemable stock. The exception is if redemption is required upon liquidation or termination of the reporting entity.

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Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

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