Note 18 - Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Net operating loss carryforwards	$ 240	$ 258
Postretirement benefits, including pensions	92	87
Research and development costs	149	124
Expense accruals	76	81
Other tax credits recoverable	234	244
Capital loss carryforwards	47	42
Inventory reserves	25	19
Postemployment and other benefits	5	6
Intangibles	17
Leasing activities	43	46
Total	928	907
Valuation allowances	(259)	(190)
Deferred tax assets	669	717
Unremitted earnings	(10)	(4)
Intangibles		(34)
Depreciation	(87)	(104)
Other		(33)
Deferred tax liabilities	(97)	(175)
Net deferred tax assets	$ 572	$ 542