Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2020

Fair Value Disclosures [Abstract]

Assets and liabilities measured at fair value on a recurring basis

The following tables present the Company’s assets and liabilities that are measured at fair value on a recurring basis at March 31, 2020, and December 31, 2019:

				Fair value measurements at reporting date using:
				Quoted prices in active markets for identical assets		Significant other observable inputs			Significant unobservable inputs
Description	March 31, 2020			(Level 1)		(Level 2)			(Level 3)
Assets	(in millions)
Cash equivalents
Cash equivalents (a)	$	3,495		$	3,495	$	—		$	—
Commercial paper	360			—		360			—
Certificates of deposit	19			—		19			—
Time deposits	66			—		66			—
Short-term investments:
Treasury bills	1,396			1,396		—			—
Certificates of deposit	184			—		184			—
Time deposits	25			—		25			—
Interest rate derivatives (see Note 4)	4					4
Fuel derivatives:
Option contracts (b)	85			—		—			85
Other available-for-sale securities	182			182		—			—
Total assets	$	5,816		$	5,073	$	658		$	85
Liabilities
Interest rate derivatives (see Note 4)	$	(71	)	$	—	$	(71	)	$	—

(a) Cash equivalents are primarily composed of money market investments.

(b) In the unaudited Condensed Consolidated Balance Sheet amounts are presented as an asset. See Note 4.

				Fair value measurements at reporting date using:
				Quoted prices in active markets for identical assets		Significant other observable inputs			Significant unobservable inputs
Description	December 31, 2019			(Level 1)		(Level 2)			(Level 3)
Assets	(in millions)
Cash equivalents
Cash equivalents (a)	$	1,999		$	1,999	$	—		$	—
Commercial paper	535			—		535			—
Certificates of deposit	14			—		14			—
Short-term investments:
Treasury bills	1,196			1,196		—			—
Certificates of deposit	268			—		268			—
Time deposits	60			—		60			—
Interest rate derivatives (see Note 4)	2			—		2			—
Fuel derivatives:
Option contracts (b)	110			—		—			110
Other available-for-sale securities	197			197		—			—
Total assets	$	4,381		$	3,392	$	879		$	110
Liabilities
Interest rate derivatives (see Note 4)	$	(6	)	$	—	$	(6	)	$	—

(a) Cash equivalents are primarily composed of money market investments.

(b) In the unaudited Condensed Consolidated Balance Sheet amounts are presented as a net asset. See Note 4.

Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation

The following tables present the Company’s activity for items measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the three months ended March 31, 2020 and the year ended December 31, 2019:

Fair value measurements using significant unobservable inputs (Level 3)
(in millions)	Fuel derivatives
Balance at December 31, 2019	$	110
Total losses for the period
Included in earnings	(2		)	(a)
Included in other comprehensive income	(106		)
Purchases	83			(b)
Balance at March 31, 2020	$	85
The amount of total losses for the period   included in earnings attributable to the   change in unrealized gains or losses relating   to assets still held at March 31, 2020	$	(2	)	(a)
The amount of total losses for the period   included in other comprehensive loss attributable to the   change in unrealized gains or losses relating   to assets still held at March 31, 2020	$	(100	)

(a) Included in Other (gains) losses, net, within the unaudited Condensed Consolidated Statement of Comprehensive Income (Loss).

(b) The purchase of fuel derivatives is recorded gross based on the structure of the derivative instrument and whether a contract with multiple derivatives was purchased as a single instrument or separate instruments.

Fair value measurements using significant unobservable inputs (Level 3)
(in millions)	Fuel derivatives
Balance at December 31, 2018	$	138
Losses included in other comprehensive loss	(112		)
Purchases	133			(a)
Sales	(2		)	(a)
Settlements	(47		)
Balance at December 31, 2019	$	110

(a) The purchase and sale of fuel derivatives are recorded gross based on the structure of the derivative instrument and whether a contract with multiple derivatives was purchased as a single instrument or separate instruments.

Fair Value Valuation Techniques

The following table presents a range and weighted average of the unobservable inputs utilized in the fair value measurements of the Company’s fuel derivatives classified as Level 3 at March 31, 2020:

Quantitative information about Level 3 fair value measurements
	Valuation technique	Unobservable input	Period (by year)	Range	Weighted Average (a)
Fuel derivatives	Option model	Implied volatility	Second quarter 2020	49-121%	93	%
			Third quarter 2020	50-73%	59	%
			Fourth quarter 2020	41-56%	47	%
			2021	28-47%	36	%
			2022	27-30%	28	%
			Beyond 2022	25-27%	26	%

(a) Implied volatility weighted by the notional amount (barrels of fuel) that will settle in respective period.

Fair value, by Balance Sheet Grouping

The carrying amounts and estimated fair values of the Company’s short-term and long-term debt (including current maturities), as well as the applicable fair value hierarchy tier, at March 31, 2020, are presented in the table below. The fair values of the Company’s publicly held long-term debt are determined based on inputs that are readily available in public markets or can be derived from information available in publicly quoted markets; therefore, the Company has categorized these agreements as Level 2. Debt under five of the Company’s debt agreements is not publicly held. The Company has determined the estimated fair value of this debt to be Level 3, as certain inputs used to determine the fair value of these agreements are unobservable. The Company utilizes indicative pricing from counterparties and a discounted cash flow method to estimate the fair value of the Level 3 items.

(in millions)	Carrying value		Estimated fair value		Fair value level hierarchy
2.65% Notes due 2020	$	504	$	495	Level 2
Term Loan Agreement payable through 2020 - 5.223%	120		120		Level 3
737 Aircraft Note payable through 2020	7		7		Level 3
Revolving Credit Facility	1,000		978		Level 3
Term Loan Agreement due 2021 - 3.000%	1,000		990		Level 3
2.75% Notes due 2022	300		283		Level 2
Pass Through Certificates due 2022 - 6.24%	168		167		Level 2
Term Loan Agreement payable through 2026 - 3.03%	178		164		Level 3
3.00% Notes due 2026	300		284		Level 2
3.45% Notes due 2027	300		264		Level 2
7.375% Debentures due 2027	121		139		Level 2
2.625% Notes due 2030	500		420		Level 2