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Consolidated Statements Of Changes In Shareholders' Equity (Parenthetical) - $ / shares | 3 Months Ended
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Mar. 31, 2018 | Mar. 31, 2017
Common stock dividends per share, declared | $ 0.24 | $ 0.21
Series A 3% Preferred Stock [Member] |  |
Preferred stock dividends per share, declared | $ 0.75 | $ 0.75
Preferred stock, dividend percentage | 3.00% | 3.00%
Series B-1 8.48% Preferred Stock [Member] |  |
Preferred stock dividends per share, declared | $ 2.12 | $ 2.12
Preferred stock, dividend percentage | 8.48% | 8.48%

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- Definition Aggregate dividends declared during the period for each share of common stock outstanding. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 + Details
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