Note 5 - Gross Carrying Amount and Accumulated Amortization by Major Intangible Asset Category (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Accumulated Amortization	$ 89	$ 84
Intangible Assets Net	21
Intangible assets gross	128	131
Intangible assets net	39	47
Trade Names [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	18	21
Technology-Based Intangible Assets [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	99	99
Accumulated Amortization	80	76
Intangible Assets Net	$ 19	$ 23
Weighted-Average Amortization Period	5 years	5 years
Customer-Related Intangible Assets [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 11	$ 11
Accumulated Amortization	9	8
Intangible Assets Net	$ 2	$ 3
Weighted-Average Amortization Period	3 years	4 years