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Income Taxes Income Taxes - Reconciliation of Unrecognized Tax Benefits (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Reconciliation of Unrecognized Tax Benefits [Line Items] |  |  |
AACNetTaxableIncomeFromTierB | $ 1,029 |  |
Unrecognized Tax Benefits, Interest on Income Taxes Accrued | 0 | $ 0 | $ 0
Reconciliation of Unrecognized Tax Benefits [Roll Forward] |  |  |
Unrecognized Tax Benefits | 0 | 0 | 0
Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions | 0 | 0 | 0
Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions | 0 | 0 | 0
Unrecognized Tax Benefits | 0 | 0 | 0
UnrecognizedTaxBenefitsInterestOnIncomeTaxesPaid | $ 0 | $ 0 | $ 0

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- Definition [Line Items] for Reconciliation of Unrecognized Tax Benefits [Table] + References No definition available. + Details
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- Definition Amount of unrecognized tax benefits. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 45 -Paragraph 10B -URI http://asc.fasb.org/extlink&oid=116821951&loc=SL37586934-109318 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319 + Details
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- Definition Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319 + Details
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