Note 13 - Revenue (Details Textual) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Disaggregation Of Revenue [Line Items]
Contract liabilities	$ 60		$ 60		$ 61
Contract liabilities, current	44		44		43
Revenue recognized, contract liabilities	4	$ 4	35	$ 34
Contract with customer, cash payments received for liabilities that have been deferred	21	$ 26	31	$ 43
Other Current Assets [Member]
Disaggregation Of Revenue [Line Items]
Contract assets	2		2		4
Other Current Liabilities [Member]
Disaggregation Of Revenue [Line Items]
Contract liabilities, current	44		44		43
Other Long-Term Liabilities [Member]
Disaggregation Of Revenue [Line Items]
Contract liabilities, non-current	$ 16		$ 16		$ 18