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Stock Compensation - Stock Compensation Fair Value of stock options granted assumptions used (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Risk free interest rate	2.00%	3.79%	3.09%
Expected dividend yield	2.20%	2.90%	2.86%
Expected life of award (years)	5 years 4 months 24 days	6 years	5 years 2 months 12 days
Expected volatility	50.00%	50.72%	48.77%
Fair value per option share (in dollars per share)	$ 4.93	$ 3.69	$ 3.01

The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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