Annual report pursuant to Section 13 and 15(d)

BENEFIT PLANS (Weighted-Average Assumptions used to Determine Net Periodic Benefit Cost) (Details)

v3.8.0.1
BENEFIT PLANS (Weighted-Average Assumptions used to Determine Net Periodic Benefit Cost) (Details)
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Pension Benefits      
Weighted-average assumptions used to determine net periodic benefit cost at December 31,      
Discount rate 4.23% 4.86% 4.26%
Expected return on plan assets 7.14% 7.14% 7.44%
Rate of compensation increase 4.88% 4.80% 4.71%
Other Benefits      
Weighted-average assumptions used to determine net periodic benefit cost at December 31,      
Discount rate 3.98% 4.39% 4.05%
Expected return on plan assets 7.25% 7.25% 7.50%