Note 4 - Long-term Debt - Long-term Debt Summary (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Long-term debt, gross	$ 4,035	$ 4,035
Unamortized premium	3	3
Long-term debt, less current portion and deferred financing costs	3,976	3,974
Borrowing availability under 2019 Revolving Credit Facility	299	200
The 2017 Term Loan [Member]
Long-term debt, gross	595	595
The 2019 Term Loan [Member]
Long-term debt, gross	1,190	1,190
2026 Notes [Member]
Long-term debt, gross	700	700
Unamortized deferred loan costs	(6)	(6)
2027 Notes [Member]
Long-term debt, gross	750	750
Unamortized deferred loan costs	(10)	(10)
2030 Notes [Member]
Long-term debt, gross	800	800
Unamortized deferred loan costs	(13)	(14)
The 2019 Senior Credit Facility [Member]
Long-term debt, gross	1,785
Unamortized deferred loan costs	$ (33)	$ (34)

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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