XML 42 R56.htm IDEA: XBRL DOCUMENT

Shareholders' Equity, Stock Plans and Preferred Stock (Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Wieghted Average Grant Date Fair Value) (Details)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividends	3.75%	3.93%	3.22%
Weighted average expected term (years)	6 years	6 years	6 years
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility (range)	58.00%	59.00%	62.00%
Risk free interest rate (range)	0.80%	1.02%	2.21%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility (range)	59.00%	60.00%	89.00%
Risk free interest rate (range)	1.03%	1.30%	3.28%

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.

+ References+ Details