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Consolidated Statement of Changes in Stockholders' Equity (Parenthetical) - $ / shares | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2019 | Mar. 31, 2019 | Jun. 30, 2018 | Mar. 31, 2018 | Jun. 30, 2019 | Jun. 30, 2018
Statement of Stockholders' Equity [Abstract] |  |  |  |  |  |
Common shares purchased and retired (in shares) | 607 |  | 896 |  | 39,360 | 22,596
Common shares issued (in shares) | 4,356,498 |  | 11,389 |  | 4,356,498 | 11,389
Non-vested common shares issued (in shares) | 11,136 |  |  |  | 211,164 | 204,991
Non-vested common shares forfeited (in shares) | 16,032 |  | 10,566 |  | 21,417 | 27,147
stock options exercised (in shares) | 41,704 |  | 60,852 |  | 98,686 | 127,998
Shares tendered (in shares) | 16,104 |  | 4,260 |  | 35,108 | 24,729
Common dividends (in dollars per share) | $ 0.31 | $ 0.28 | $ 0.56 | $ 0.62 |  |

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