Consolidated Statements of Changes in Shareholders' Equity (Parenthetical) (Unaudited) - $ / shares	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement Consolidated Statements Of Changes In Shareholders Equity Parenthetical Unaudited [Abstract]
Cash dividend declared per share	$ 0.11	$ 0.08	$ 0.22	$ 0.23
Treasury shares purchased shares			70,181

Number of shares that have been repurchased during the period and are being held in treasury.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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-SubTopic 10
-Section S99
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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration