Consolidated Statements of Changes in Stockholders' Equity (Parentheticals)	12 Months Ended
Dec. 31, 2017 $ / shares	Dec. 31, 2016 $ / shares	Dec. 31, 2015 $ / shares
Common Stock [Member] \| Stock Split From [Member]
Stock split		2
Cash dividends declared (in dollars per share)	$ 0.80	$ 0.72	$ 0.64
Stock split		3

Ratio applied to the conversion of stock split, for example but not limited to, one share converted to two or two shares converted to one.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SAB TOPIC 4.C)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187143-122770

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