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Consolidated Statements of Stockholders' Equity (unaudited) (Parenthetical) - $ / shares | 6 Months Ended
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Jun. 30, 2018 | Jun. 30, 2017
Consolidated Statements of Stockholders' Equity (unaudited) [Abstract] |  |
Cash dividends - per share (in dollars per share) | $ 0.48 | $ 0.46
Net issuance of shares to employee benefit plans and other stock plans (in shares) | 104,390 | 252,312

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- Definition Number of shares issued during the period to an employee benefit plans and other stock plans. + References No definition available. + Details
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- Definition The per share amount of a dividend declared, but not paid, as of the financial reporting date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586 + Details
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