XML 93 R63.htm IDEA: XBRL DOCUMENT v3.8.0.1
Note 8 - Employee Benefit Plans - Benefit Obligation and Prepaid Benefit Costs Assumptions (Details)
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Discount rate: net periodic pension cost 4.14% 4.45%
Discount rate: projected benefit obligation 3.83% 4.14%
Expected rate of return on plan assets 6.62% 7.20%
Rate of compensation increase: net periodic pension cost 2.00% 2.00%
Assumed for after 2018 [Member]    
Rate of compensation increase: net periodic pension cost [1] 2.00% 2.00%
Assumed for 2016 Through 2018 [Member]    
Rate of compensation increase: net periodic pension cost [1]   0.00%
[1] 0% was assumed for years 2016 through 2018 and 2% was assumed thereafter.