Note 10 - Revenue (Details Textual) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Disaggregation Of Revenue [Line Items]
Contract liabilities	$ 61		$ 61		$ 64
Revenue recognized, contract liabilities	6	$ 5	31	$ 31
Contract with customer, cash payments received for liabilities that have been deferred	22	$ 19	26	$ 21
Other Current Assets [Member]
Disaggregation Of Revenue [Line Items]
Contract assets	2		2		2
Other Current Liabilities [Member]
Disaggregation Of Revenue [Line Items]
Contract liabilities, current	45		45		47
Other Long-Term Liabilities [Member]
Disaggregation Of Revenue [Line Items]
Contract liabilities, non-current	$ 16		$ 16		$ 17