Note 7 - Pension and Post-retirement Benefits (Details Textual) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment	$ (6.9)
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	4.31%	3.77%
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Curtailment	$ 4.2
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	4.0
Pension Plan [Member] | Domestic Plan [Member]
Defined Benefit Plan, Plan Assets, Contributions by Employer	0.4
Pension Plan [Member] | Foreign Plan [Member]
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 0.2