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Fair Value Measurements - Unobservable Data Used in Recurring Valuations of Level 3 (Detail) $ in Millions | Jun. 30, 2021 USD ($) | Dec. 31, 2020 USD ($)
--- | --- | ---
Interest Rate Swaps [Member] |  |
Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] |  |
Derivative financial instruments, Fair Value | $ 254 | $ 315
Cross-Currency Interest Rate Swaps [Member] |  |
Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] |  |
Derivative financial instruments, Fair Value | (108) | $ (294)
Level 3 [Member] |  |
Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] |  |
Derivative financial instruments, Fair Value | (114) |
Level 3 [Member] | Cross-Currency Interest Rate Swaps [Member] |  |
Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] |  |
Derivative financial instruments, Fair Value | $ (108) |
Derivative Asset (Liability) Net, Valuation Technique [Extensible List] | us-gaap:ValuationTechniqueDiscountedCashFlowMember |
Derivatives | 0.05 |
Derivative Asset (Liability) Net, Measurement Input [Extensible List] | Constant Prepayment Rate [Member] |
Level 3 [Member] | Prime/LIBOR Basis Swaps [Member] | Interest Rate Swaps [Member] |  |
Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] |  |
Derivative financial instruments, Fair Value | $ (6) |
Derivative Asset (Liability) Net, Valuation Technique [Extensible List] | us-gaap:ValuationTechniqueDiscountedCashFlowMember |
Level 3 [Member] | Prime/LIBOR Basis Swaps [Member] | Interest Rate Swaps [Member] | Constant Prepayment Rate [Member] |  |
Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] |  |
Derivatives | 0.09 |
Level 3 [Member] | Prime/LIBOR Basis Swaps [Member] | Interest Rate Swaps [Member] | Bid/ask adjustment to discount rate [Member] |  |
Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] |  |
Derivatives | 0.0008 |

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