Note 13 - Revenue (Details Textual) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Disaggregation Of Revenue [Line Items]
Contract liabilities	$ 55		$ 55		$ 61
Contract liabilities, current	40		40		43
Revenue recognized, contract liabilities	5	$ 5	31	$ 30
Contract with customer, cash payments received for liabilities that have been deferred	19	$ 20	21	$ 23
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	40		40		43
Other Long-Term Liabilities [Member]
Disaggregation Of Revenue [Line Items]
Contract liabilities, non-current	$ 15		$ 15		$ 18