XML 92 R71.htm IDEA: XBRL DOCUMENT v3.8.0.1
STOCK PLANS (Summary Non-Vested Restricted Stock Activity) (Details) - Restricted stock awards
 12 Months Ended
Dec. 31, 2017
$ / shares
shares
Shares  
Balance at beginning of year (in shares) | shares 46,159
Shares granted | shares 13,910
Shares vested (in shares) | shares (12,213)
Balance at end of year (in shares) | shares 47,856
Weighted Average Grant Date Fair Value  
Balance at beginning of year, weighted average grant date fair value (in dollars per share) | $ / shares $ 64.65
Shares granted, weighted average grant date fair value (in dollars per share) | $ / shares 89.82
Shares vested, weighted average grant date fair value (in dollars per share) | $ / shares 90.37
Balance at end of year, weighted average grant date fair value (in dollars per share) | $ / shares $ 71.54