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STOCK OWNERSHIP AND COMPENSATION PLANS (Weighted Average Assumptions Used in Valuing Options Granted) (Details) - $ / shares
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Fair value at grant date $ 15.98 $ 10.35 $ 11.57
Expected volatility 19.80% 21.60% 21.00%
Dividend yield 1.90% 2.40% 2.10%
Risk-free interest rate 2.10% 1.40% 1.70%
Expected holding period, in years 5 years 2 months 12 days 5 years 3 months 18 days 5 years 3 months 18 days