Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Common stock, no par value
Common stock, shares authorized	6,500,000	6,500,000
Common stock, shares issued	5,200,000	5,200,000
Common stock, shares outstanding	5,200,000	5,200,000
Treasury stock, shares	587,466	572,662

Face amount per share of no-par value common stock.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.29)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 30
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Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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-Publisher FASB
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Number of common and preferred shares that were previously issued and that were repurchased by the issuing entity and held in treasury on the financial statement date. This stock has no voting rights and receives no dividends.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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-Section S99
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