Note 10 - Pension and Postretirement Benefit Plans (Details Textual) - UNITED STATES - Pension Plan [Member] - Terminated Plan [Member] $ in Millions	1 Months Ended	12 Months Ended
	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)	Oct. 31, 2017
Number of Plans Terminated			1
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 59
Defined Benefit Plan, Funded (Unfunded) Status of Plan, Total	$ 165
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement		$ 256