Note 16 - Pension and Postretirement Benefit Plans - Benefit Payments Which Reflect Expected Future Services, Expected to Be Paid Over Next Ten Years (Details)
$ in Thousands
Dec. 31, 2016
USD ($)
SERP I and SERP II [Member]  
2017 $ 259
2018 257
2019 256
2020 254
2021 250
2022-2026 1,671
PRBP [Member]  
2017 78
2018 68
2019 59
2020 50
2021 42
2022-2026 $ 125