Dividends and Basic Earnings Per Common Share (Details) (USD $)	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Dividends and Basic Earnings Per Common Share [Abstract]
Cash dividends	$ 0	$ 0
Earnings per share for the period [Abstract]
Net Income	$ 6,251,000	$ 6,190,000
Average Number of Common Shares Outstanding (in shares)	777,882	779,296
Basic Earnings Per Common Share Amount (in dollars per share)	$ 8.04	$ 7.94

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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+ Details

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

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+ Details

- Definition

Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Publisher FASB

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-Glossary Weighted-Average Number of Common Shares Outstanding

-URI http://asc.fasb.org/extlink&oid=6528421

+ Details