Note 16 - Reportable Segments (Details Textual) - USD ($) $ in Millions	3 Months Ended					6 Months Ended
	Jun. 30, 2021		Jun. 30, 2020		Mar. 31, 2020	Jun. 30, 2021		Jun. 30, 2020
Number of Material Formations						150
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%		21.00%			21.00%		21.00%
Revenue, Cumulative Adjustments		[1]		[1]	$ 105		[1]	$ 105	[1]

[1] Amount represents the negative impact of a cumulative adjustment to reduce revenue by $105 million recorded during the first quarter of 2020. The adjustment was associated with a previously recorded commercial benefit asset, reflected as a prepayment, to a customer with a long-term supply agreement that substantially exited its production of LCD panels.