Note 11 - Commitments and Contingencies (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2020
Commitments And Contingencies Disclosure [LineItems]
Asset retirement obligations	$ 43	$ 43
U S International Development Finance Corporation [Member]
Commitments And Contingencies Disclosure [LineItems]
Line of Credit Facility, Maximum Borrowing Capacity			$ 765
BRAZIL
Commitments And Contingencies Disclosure [LineItems]
Restricted Cash and Investments, Noncurrent	6	$ 8
Federal And State Value Added Taxes Litigations And Civil Litigation And Disputes With Former Employees [Member] | BRAZIL
Commitments And Contingencies Disclosure [LineItems]
Restricted Cash	100
Loss Contingency Accrual	4
Aggregate Claims	79
Loss Contingency, Estimate of Possible Loss	4
Restricted Cash and Investments, Noncurrent	6
Assets, Noncurrent	35
Bank Guarantees And Letters Of Credit [Member]
Commitments And Contingencies Disclosure [LineItems]
Guarantor Obligations, Maximum Exposure, Undiscounted	2
Surety Bond [Member]
Commitments And Contingencies Disclosure [LineItems]
Guarantor Obligations, Maximum Exposure, Undiscounted	47
L C Facility Agreement [Member]
Commitments And Contingencies Disclosure [LineItems]
Letters of Credit Outstanding, Amount	$ 27