Note 10 - Revenue (Details Textual) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Disaggregation Of Revenue [Line Items]
Contract liabilities	$ 57		$ 64
Revenue recognized, contract liabilities	25	$ 26
Contract with customer, cash payments received for liabilities that have been deferred	19	$ 19
Other Current Assets [Member]
Disaggregation Of Revenue [Line Items]
Contract assets	1		2
Other Current Liabilities [Member]
Disaggregation Of Revenue [Line Items]
Contract liabilities, current	41		47
Other Long-Term Liabilities [Member]
Disaggregation Of Revenue [Line Items]
Contract liabilities, non-current	$ 16		$ 17