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CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Parenthetical) - shares | 9 Months Ended
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Sep. 30, 2017 | Sep. 24, 2016
Statement of Stockholders' Equity [Abstract] |  |
Purchase of treasury shares, shares acquired (in shares) | 384,622 | 245,789
Stock plan exercises; shares acquired (in shares) | 19,086 | 10,747
Stock options exercised; shares issued (in shares) | 84,432 | 62,535
Stock awards; shares issued (in shares) | 5,677 | 6,976

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