Note 12 - Revenue (Details Textual) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Disaggregation Of Revenue [Line Items]
Contract liabilities	$ 61		$ 61		$ 48
Contract liabilities, current	32		32		34
Revenue recognized, contract liabilities	4	$ 1	34	$ 29
Contract with customer, cash payments received for liabilities that have been deferred	26	$ 23	43	$ 31
Other Current Assets [Member]
Disaggregation Of Revenue [Line Items]
Contract assets	2		2		3
Other Current Liabilities [Member]
Disaggregation Of Revenue [Line Items]
Contract liabilities, current	42		42		42
Other Long-Term Liabilities [Member]
Disaggregation Of Revenue [Line Items]
Contract liabilities, non-current	$ 19		$ 19		$ 6