Long-Term and Other Debt - Gain (Loss) on Debt Financing Transactions (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Debt Disclosure [Abstract]
Repurchase and cancellation of principal balance at premium	$ 0	$ 80	$ 110
Unamortized debt (premium) discount and deferred financing costs. net	0	20	(30)
Third party debt issuance fees	1	0	13
Loss on debt financing transactions	$ 1	$ 100	$ 93

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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