Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

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Amount before tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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The estimated net amount of unrealized gains or losses on price risk cash flow hedges as of the balance sheet date expected to be reclassified to earnings within the next twelve months.

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DERIVATIVE INSTRUMENTS - INCOME STATEMENT (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Gains (losses) recognized in interest income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Loss expected to be reclassified	$ 10
Derivative Instruments Not Designated as Hedges [Member] \| Fuel hedge contracts [Member] \| Gains (losses) recognized in aircraft fuel expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Losses recognized in income	(10)	$ (10)	$ 1
Cash Flow Hedging [Member] \| Derivative Instruments Designated as Hedges [Member] \| Interest rate swaps agreements [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Losses in accumulated other comprehensive loss	(21)	(13)	0
Cash Flow Hedging [Member] \| Derivative Instruments Designated as Hedges [Member] \| Interest rate swaps agreements [Member] \| Gains (losses) recognized in aircraft rent [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Losses recognized in income	$ (3)	$ (3)	$ (3)