Stock Compensation - Options (Details) (USD $)	6 Months Ended
Jun. 30, 2012
Summary of stock option activity
Outstanding beginning of period, Options	66,693
Granted, Options
Granted, Weighted-Average Exercise Prices Per Share
Exercised, Options	(5,013)
Forfeited/Cancelled, Options	(2,613)
Outstanding end of period, Options	59,067
Options exercisable end of period, Options	59,067
Outstanding beginning of period, Weighted-Average Exercise Prices Per Share	$ 27.32
Exercised, Weighted-Average Exercise Prices Per Share	$ 24.49
Forfeited/Cancelled, Weighted-Average Exercise Prices Per Share	$ 24.49
Outstanding end of period, Weighted-Average Exercise Prices Per Share	$ 27.69
Options exercisable end of period, Weighted-Average Exercise Prices Per Share	$ 27.69

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired.

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Gross number of share options (or share units) granted during the period.

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The number of shares reserved for issuance under stock option agreements awarded under the plan that validly exist and are outstanding as of the balance sheet date, including vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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