XML 127 R106.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Stock Compensation Plans: Fair Value Assumptions (Details) - Stock Options - $ / shares
12 Months Ended
Sep. 30, 2019
Sep. 30, 2018
Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected volatility (as a percent) 29.00% 17.00% 16.00%
Expected life (in years) 5 years 5 years 5 years
Expected dividend yield (as a percent) 3.28% 2.61% 1.85%
Risk free interest rate (as a percent) 1.53% 2.97% 1.89%
Grant date fair value per share (in dollars per share) $ 5.116 $ 4.48 $ 3.84