XML 69 R55.htm IDEA: XBRL DOCUMENT v3.3.1.900
Note 13 - Stock Options Valuation Assumptions (Details) - $ / shares
 12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Expected option life in years(1) 6 years 6 years 6 years 36 days
Expected stock price volatility percentage(2) [1] 25.00% 27.00% 33.00%
Risk-free interest rate percentage(3) [2] 1.80% 1.90% 1.50%
Expected dividend yield(4) [3] 0.44% 0.46% 0.51%
Fair value as of the date of grant (in dollars per share) $ 5.96 $ 6.25 $ 5.46
[1] We use our stock’s historical volatility for the same period of time as the expected life. We have no reason to believe that its future volatility will differ from the past.
[2] The rate is based on the U.S. Treasury yield curve in effect at the time of the grant for the same period of time as the expected life.
[3] The calculation is based on the total expected annual dividend payout divided by the average stock price.