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Consolidated Statements of Stockholders' Equity (unaudited) (Parenthetical) - $ / shares | 3 Months Ended
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Mar. 31, 2020 | Mar. 31, 2019
Consolidated Statements of Stockholders' Equity (unaudited) [Abstract] |  |
Cash dividends - per share (in dollars per share) | $ 0.54 | $ 0.52
Purchase of treasury shares (in shares) | 263,507 |
Net issuance of shares to employee benefit plans and other stock plans (in shares) | 54,341 | 66,920

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