Note 10 - Fair Value - Fair Value of Financial Instruments (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Reported Value Measurement [Member]
Non-qualified employee benefit plan investments	$ 22	$ 26
Investment in Venator	46	32
Option agreement for remaining Venator shares	(26)	11
Long-term debt (including current portion)	(1,565)	(2,121)
Estimate of Fair Value Measurement [Member]
Non-qualified employee benefit plan investments	22	26
Investment in Venator	46	32
Option agreement for remaining Venator shares	(26)	11
Long-term debt (including current portion)	$ (1,738)	$ (2,334)

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

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Carrying amount as of the balance sheet date of assets held under deferred compensation agreements.

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair value portion of investments accounted under the equity method.

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