FAIR VALUE MEASUREMENTS

Accounting standards pertaining to fair value measurements establish a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value. These tiers include: Level 1, defined as observable inputs such as quoted prices in active markets; Level 2, defined as inputs other than quoted prices in active markets that are either directly or indirectly observable; and Level 3, defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions.

As of December 31, 2015, the Company held certain items that are required to be measured at fair value on a recurring basis. These included cash equivalents, short-term investments (primarily treasury bills and certificates of deposit), interest rate derivative contracts, fuel derivative contracts, and available-for-sale securities. The majority of the Company’s short-term investments consist of instruments classified as Level 1. However, the Company has certificates of deposit, commercial paper, and Eurodollar time deposits that are classified as Level 2, due to the fact that the fair value for these instruments is determined utilizing observable inputs in non-active markets. Other available-for-sale securities primarily consist of investments associated with the Company’s excess benefit plan.

The Company’s fuel and interest rate derivative instruments consist of over-the-counter contracts, which are not traded on a public exchange. Fuel derivative instruments include swaps, as well as different types of option contracts, whereas interest rate derivatives consist solely of swap agreements. See Note 10 for further information on the Company’s derivative instruments and hedging activities. The fair values of swap contracts 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 swap contracts as Level 2. The Company’s Treasury Department, which reports to the Chief Financial Officer, determines the value of option contracts utilizing an option pricing model based on inputs that are either readily available in public markets, can be derived from information available in publicly quoted markets, or are provided by financial institutions that trade these contracts. The option pricing model used by the Company is an industry standard model for valuing options and is the same model used by the broker/dealer community (i.e., the Company’s counterparties). The inputs to this option pricing model are the option strike price, underlying price, risk free rate of interest, time to expiration, and volatility. Because certain inputs used to determine the fair value of option contracts are unobservable (principally implied volatility), the Company has categorized these option contracts as Level 3. Volatility information is obtained from external sources, but is analyzed by the Company for reasonableness and compared to similar information received from other external sources. The fair value of option contracts considers both the intrinsic value and any remaining time value associated with those derivatives that have not yet settled. The Company also considers counterparty credit risk and its own credit risk in its determination of all estimated fair values. To validate the reasonableness of the Company’s option pricing model, on a monthly basis, the Company compares its option valuations to third party valuations. If any significant differences were to be noted, they would be researched in order to determine the reason. However, historically, no significant differences have been noted. The Company has consistently applied these valuation techniques in all periods presented and believes it has obtained the most accurate information available for the types of derivative contracts it holds.

Included in Other available-for-sale securities are the Company's investments associated with its excess benefit plan which consist of mutual funds that are publicly traded and for which market prices are readily available. This plan is a non-qualified deferred compensation plan designed to hold Employee contributions in excess of limits established by Section 415 of the Internal Revenue Code of 1986, as amended. Payments under this plan are made based on the participant's distribution election and plan balance. Assets related to the funded portion of the deferred compensation plan are held in a rabbi trust, and the Company remains liable to these participants for the unfunded portion of the plan. The Company records changes in the fair value of the asset in the Company's earnings.

The following tables present the Company’s assets and liabilities that are measured at fair value on a recurring basis at December 31, 2015, and December 31, 2014:



				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, 2015			(Level 1)		(Level 2)			(Level 3)
Assets	(in millions)
Cash equivalents
Cash equivalents (a)	$	1,337		$	1,337	$	—		$	—
Commercial paper	200			—		200			—
Certificates of deposit	13			—		13			—
Eurodollar Time Deposits	33			—		33			—
Short-term investments:
Treasury bills	1,248			1,248		—			—
Certificates of deposit	220			—		220			—
Interest rate derivatives (see Note 10)	2			—		2			—
Fuel derivatives:
Swap contracts (b)	38			—		38			—
Swap contracts (c)	931			—		931			—
Option contracts (b)	10			—		—			10
Option contracts (c)	956			—		—			956
Other available-for-sale securities	93			66		—			27
Total assets	$	5,081		$	2,651	$	1,437		$	993
Liabilities
Fuel derivatives:
Swap contracts (c)	$	(774	)	$	—	$	(774	)	$	—
Option contracts (b)	(26		)	—		—			(26		)
Option contracts (c)	(2,616		)	—		—			(2,616		)
Interest rate derivatives (see Note 10)	(49		)	—		(49		)	—
Total liabilities	$	(3,465	)	$	—	$	(823	)	$	(2,642	)

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

(b) In the Consolidated Balance Sheet amounts are presented as a net asset. See Note 10.



				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, 2014			(Level 1)		(Level 2)			(Level 3)
Assets	(in millions)
Cash equivalents
Cash equivalents (a)	$	1,110		$	1,110	$	—		$	—
Commercial paper	70			—		70			—
Certificates of deposit	4			—		4			—
Eurodollar Time Deposits	98			—		98			—
Short-term investments:
Treasury bills	1,450			1,450		—			—
Certificates of deposit	256			—		256			—
Interest rate derivatives (see Note 10)	13			—		13			—
Fuel derivatives:
Swap contracts (b)	455			—		455			—
Option contracts (b)	892			—		—			892
Other available-for-sale securities	95			63		—			32
Total assets	$	4,443		$	2,623	$	896		$	924
Liabilities
Fuel derivatives:
Swap contracts (b)	$	(365	)	$	—	$	(365	)	$	—
Option contracts (b)	(1,983		)	—		—			(1,983		)
Interest rate derivatives (see Note 10)	(61		)	—		(61		)	—
Total liabilities	$	(2,409	)	$	—	$	(426	)	$	(1,983	)

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

(b) In the Consolidated Balance Sheet amounts are presented as a net liability. See Note 10.

The Company had no transfers of assets or liabilities between any of the above levels during the years ended December 31, 2015 or 2014. The Company did not have any assets or liabilities measured at fair value on a nonrecurring basis as of December 31, 2015 or 2014. 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 2015 and 2014:



	Fair value measurements using significant unobservable inputs (Level 3)
	Fuel				Other
(in millions)	derivatives				securities			Total
Balance at December 31, 2014	$	(1,091	)		$	32		$	(1,059	)
Total losses (realized or unrealized)
Included in earnings	(646		)		(1		)	(647		)
Included in other comprehensive income	(858		)		—			(858		)
Purchases	750			(a)	—			750
Sales	(196		)	(a)	(4		)	(200		)
Settlements	365				—			365
Balance at December 31, 2015	$	(1,676	)		$	27		$	(1,649	)
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 December 31, 2015	$	(428	)		$	—		$	(428	)

(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 is purchased as a single instrument or separate instruments.



	Fair value measurements using significant unobservable inputs (Level 3)
	Fuel				Other
(in millions)	derivatives				securities			Total
Balance at December 31, 2013	$	172			$	44		$	216
Total gains or (losses) (realized or unrealized)
Included in earnings	(439		)		—			(439		)
Included in other comprehensive income	(1,091		)		3			(1,088		)
Purchases	403			(a)	—			403
Sales	(155		)	(a)	(15		)	(170		)
Settlements	19				—			19
Balance at December 31, 2014	$	(1,091	)		$	32		$	(1,059	)
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 December 31, 2014	$	(450	)		$	—		$	(450	)

(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 is purchased as a single instrument or separate instruments.

The significant unobservable input used in the fair value measurement of the Company’s derivative option contracts is implied volatility. Holding other inputs constant, a significant increase (decrease) in implied volatility would result in a significantly higher (lower) fair value measurement, respectively, for the Company’s derivative option contracts.

The following table presents a range of the unobservable inputs utilized in the fair value measurements of the Company’s fuel derivatives classified as Level 3 at December 31, 2015:



Quantitative information about Level 3 fair value measurements
	Valuation technique	Unobservable input	Period (by year)	Range
Fuel derivatives	Option model	Implied volatility	2016	26-47%
			2017	25-37%
			2018	16-31%

The carrying amounts and estimated fair values of the Company’s long-term debt (including current maturities), as well as the applicable fair value hierarchy tier, at December 31, 2015, 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. Six of the Company’s debt agreements are 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
5.75% Notes due 2016	$	307	$	319	Level 2
5.25% Convertible Senior Notes due 2016	111		324		Level 2
5.125% Notes due 2017	309		321		Level 2
French Credit Agreements due 2018 - 1.53%	25		25		Level 3
Fixed-rate 737 Aircraft Notes payable through 2018 - 7.02%	17		17		Level 3
2.75% Notes due 2019	303		307		Level 2
Term Loan Agreement due 2019 - 6.315%	143		147		Level 3
Term Loan Agreement due 2019 - 4.84%	36		37		Level 3
2.65% Notes due 2020	494		493		Level 2
Term Loan Agreement due 2020 - 5.223%	329		323		Level 3
Floating-rate 737 Aircraft Notes payable through 2020	257		253		Level 3
Pass Through Certificates due 2022 - 6.24%	340		382		Level 2
7.375% Debentures due 2027	132		154		Level 2