Note 15 - Summary of Other Operating Expense (Income), Net (Details) (Parentheticals) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Mar. 31, 2017
Property, Plant and Equipment [Member]
Other Operating Income Expense Net [Line Items]
Reduced carrying value of assets			$ 8	$ 8
Finite-Lived Intangible Assets
Other Operating Income Expense Net [Line Items]
Reduced carrying value of assets			$ 12	$ 4
Other Operating Expense (Income) [Member] | Trade Names [Member]
Other Operating Income Expense Net [Line Items]
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)	$ 13	$ 2