Fair Value Measurements

Under ASC 820, Fair Value Measurements and Disclosures, disclosures relating to how fair value is determined for assets and liabilities are required, and a hierarchy for which these assets and liabilities must be grouped is established, based on significant levels of inputs, as follows:

Level 1—Quoted prices in active markets for identical assets or liabilities.

Level 2—Observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The Company utilizes several valuation techniques in order to assess the fair value of the Company’s financial assets and liabilities.

Fuel Derivative Instruments

The Company’s fuel derivative contracts generally consist of jet fuel swaps and jet fuel options. These instruments are valued using energy and commodity market data, which is derived by combining raw inputs with quantitative models and processes to generate forward curves and volatilities.

The Company utilizes the market approach to measure fair value for its fuel derivative instruments. The market approach uses prices and other relevant information generated by market transactions involving identical or comparable assets or liabilities.

The Company did not elect hedge accounting on any of the fuel derivative instruments. As a result, the Company records the fair value adjustment of its fuel derivatives in the accompanying statement of operations within aircraft fuel and on the balance sheet within prepaid expenses and other current assets or other current liabilities, depending on whether the net fair value of the derivatives is on an asset or liability position as of the respective date. Fair values of the fuel derivative instruments are determined using standard option valuation models. The Company also considers counterparty risk and its own credit risk in its determination of all estimated fair values. The Company offsets fair value amounts recognized for derivative instruments executed with the same counterparty under a master netting arrangement. The Company determines fair value of jet fuel options utilizing an option pricing model based on inputs that are either readily available in public markets or can be derived from information available in publicly quoted markets. 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.

The fair value of the Company's jet fuel swaps 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 categorizes these instruments as Level 2. Due to the fact that certain inputs utilized to determine the fair value of jet fuel options are unobservable (principally implied volatility), the Company categorizes these derivatives as Level 3. Implied volatility of a jet fuel option is the volatility of the price of the underlying commodity that is implied by the market price of the option based on an option pricing model. Thus, it is the volatility that when used in a particular pricing model, yields a theoretical value for the option equal to the current market price of that option. Implied volatility, a forward-looking measure, differs from historical volatility because the latter is calculated from known past returns. At each balance sheet date, the Company substantiates and adjusts unobservable inputs. The Company routinely assesses the valuation model's sensitivity to changes in implied volatility. Based on the Company's assessment of the valuation model's sensitivity to changes in implied volatility, it concluded that holding other inputs constant, a significant increase (decrease) in implied volatility would result in significantly higher (lower) determination of fair value measurement for the Company's aircraft fuel derivatives. As of December 31, 2015 and 2014, the Company had no outstanding jet fuel derivatives.

Interest Rate Swaps

The fair value of the Company's interest rate swaps are based on observable inputs for active swap indications in quoted markets for similar terms. The fair value of these instruments are determined using a market approach based on inputs that are readily available from public markets; therefore, the Company categorizes these instruments as Level 2. The interest rate swaps were designated as cash flow hedges and, as a result, the changes in fair value of these derivatives were recorded in accumulated other comprehensive income within the balance sheet and statement of other comprehensive income. As of December 31, 2015, the Company had no outstanding interest rate swaps. As of December 31, 2014, the interest rate swaps were recorded as a liability of approximately $1.1 million.

Long-Term Debt

The estimated fair value of the Company's non publicly held debt agreements has been determined to be Level 3 as certain inputs used to determine the fair value of these agreements are unobservable. The Company utilizes a discounted cash flow method to estimate the fair value of the Level 3 long-term debt. The estimated fair value of the Company's publicly held debt agreements has been determined to be Level 2 as the Company utilizes quoted market prices to estimate the fair value of it's public long-term debt.

The carrying amounts and estimated fair values of the Company's long-term debt, including current maturities, at December 31, 2015 and December 31, 2014, were as follows:



	As of December 31,
	2015				2014
	Carrying Value		Estimated Fair Value		Carrying Value		Estimated Fair Value		Fair value level hierarchy
	(in millions)
Senior long-term debt	$	484.2	$	477.8	$	132.0	$	132.0	Level 3
Junior long-term debt	54.3		54.6		16.0		16.1		Level 3
Class A equipment trust certificates	95.8		94.8		—		—		Level 2
Class B equipment trust certificates	25.0		25.2		—		—		Level 2
Total long-term debt	$	659.3	$	652.4	$	148.0	$	148.1

Cash and Cash Equivalents

Cash and cash equivalents at December 31, 2015 and December 31, 2014 are comprised of liquid money market funds and cash and are categorized as Level 1 instruments. The Company maintains cash with various high-quality financial institutions.

Assets and liabilities measured at gross fair value on a recurring basis are summarized below:



	Fair Value Measurements as of December 31, 2015
	Total		Level 1		Level 2		Level 3
	(in millions)
Cash and cash equivalents	$	803.6	$	803.6	$	—	$	—
Total assets	$	803.6	$	803.6	$	—	$	—

Total liabilities	$	—	$	—	$	—	$	—



	Fair Value Measurements as of December 31, 2014
	Total		Level 1		Level 2		Level 3
	(in millions)
Cash and cash equivalents	$	632.8	$	632.8	$	—	$	—
Jet fuel options	4.8		—		—		4.8
Total assets	$	637.6	$	632.8	$	—	$	4.8

Interest rate swaps	$	1.1	$	—	$	1.1	$	—
Total liabilities	$	1.1	$	—	$	1.1	$	—

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's Valuation Group is made up of individuals from the Company's Treasury and Corporate Accounting departments. The Valuation Group is responsible for the Company's valuation policies, procedures and execution thereof. The Company's Valuation Group reports to the Company's Chief Financial Officer and seeks approval for certain derivative transactions from the Audit Committee. The Valuation Group compares the results of the Company's internally developed valuation methods with counterparty reports at each balance sheet date and assesses the Company's valuation methods for accuracy and identifies any needs for modification.

The following table presents the Company’s activity for assets and liabilities measured at gross fair value on a recurring basis using significant unobservable inputs (Level 3):



	Jet Fuel Options
	(in thousands)
Balance at January 1, 2013	$	265
Total realized or unrealized gains (losses) included in earnings, net	157
Purchases	—
Sales	—
Settlements, net	(422		)
Balance at December 31, 2013	—
Total realized or unrealized gains (losses) included in earnings, net	(4,876		)
Purchases	9,679
Sales	—
Settlements, net	—
Balance at December 31, 2014	4,803
Total realized or unrealized gains (losses) included in earnings, net	(6,700		)
Purchases	2,474
Sales	—
Settlements, net	(577		)
Balance at December 31, 2015	$	—