XML 120 R107.htm IDEA: XBRL DOCUMENT v3.8.0.1
Note 12 - Pension and Other Postretirement Benefit Plans - Assumptions Used to Develop Periodic Postretirement Expense for the Postretirement Plans (Details)
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Rate of return on plan assets 0.00% 0.00% 0.00%
Weighted average discount rate 3.88% 4.06% 3.76%
Initial 8.00% 7.00% 8.00%
Ultimate (year 2023) 5.00% 5.00% 5.00%
Annual rate of salary increase for life insurance 0.00% 0.00% 0.00%