XML 119 R89.htm IDEA: XBRL DOCUMENT v3.6.0.2
Stock Based Compensation (Schedule of Fair Value Assumptions) (Details) - $ / shares
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Stock-Based Compensation [Abstract]      
Dividend yield 3.93% 3.77% 3.57%
Expected life 10 years 10 years 10 years
Expected volatility 24.84% 24.35% 24.97%
Risk-free interest rate 2.44% 2.28% 2.17%
Weighted average fair value of options granted $ 5.79 $ 4.89 $ 5.30