Long-Term and Other Debt - Gain (Loss) on Debt Financing Transactions (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
Feb. 28, 2018	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Debt Disclosure [Abstract]
Repurchase and cancellation of principal balance at premium				$ 80	$ 110	$ 0
Unamortized debt (premium) discount and deferred financing costs. net				20	(30)	26
Third party debt issuance fees				0	13	12
Loss on debt financing transactions	$ 93	$ (40)	$ 60	$ 100	$ 93	$ 38

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
-SubTopic 50
-Section 40
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=114001942&loc=d3e12355-112629

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114001942&loc=d3e12317-112629

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

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