Fair Value Measurements

Fair value is defined as the price that would be received to sell an asset or the price paid to transfer a liability in an orderly transaction between market participants at the measurement date. Fair value measurements are based upon inputs that market participants use in pricing an asset or liability, which are characterized according to a hierarchy that prioritizes those inputs based on the degree to which they are observable. Observable inputs represent market data obtained from independent sources, whereas unobservable inputs reflect a company's own market assumptions, which are used if observable inputs are not reasonably available without undue cost and effort. The three input levels of the fair value hierarchy are as follows:


•	Level 1 – quoted prices for identical assets or liabilities in active markets.


•	Level 2 – quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (e.g., interest rates) and inputs derived principally from or corroborated by observable market data by correlation or other means.


•	Level 3 – unobservable inputs for the asset or liability.

Assets and liabilities measured at fair value on a recurring basis. The fair value input hierarchy level to which an asset or liability measurement in its entirety falls is determined based on the lowest level input that is significant to the measurement in its entirety.

The following table presents the Company's assets and liabilities that are measured at fair value on a recurring basis as of September 30, 2016 for each of the fair value hierarchy levels:



	Fair Value Measurement at September 30, 2016 Using
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Fair Value at September 30, 2016
	(in millions)
Assets:
Commodity derivatives	$	—	$	180	$	—	$	180
Deferred compensation plan assets	81		—		—		81
Total assets	81		180		—		261
Liabilities:
Commodity derivatives	—		19		—		19
Interest rate derivatives	—		8		—		8
Total liabilities	—		27		—		27
Total recurring fair value measurements	$	81	$	153	$	—	$	234

Commodity derivatives. The Company's commodity derivatives represent oil, natural gas liquids ("NGL"), gas and diesel swap contracts, collar contracts and collar contracts with short puts. The asset and liability measurements for the Company's commodity derivative contracts represent Level 2 inputs in the hierarchy. The Company utilizes discounted cash flow and option-pricing models for valuing its commodity derivatives.

The asset and liability values attributable to the Company's commodity derivatives were determined based on inputs that include (i) the contracted notional volumes, (ii) independent active market price quotes, (iii) the applicable estimated credit-adjusted risk-free rate yield curve and (iv) the implied rate of volatility inherent in the collar contracts and collar contracts with short puts, which is based on active and independent market-quoted volatility factors.

Deferred compensation plan assets. The Company's deferred compensation plan assets represent investments in equity and mutual fund securities that are actively traded on major exchanges. These investments are measured based on observable prices on major exchanges. As of September 30, 2016, the significant inputs to these asset values represented Level 1 independent active exchange market price inputs.

Interest rate derivatives. The Company's interest rate derivative liabilities represent interest rate swap contracts. The Company utilizes discounted cash flow models for valuing its interest rate derivatives. The derivative values attributable to the Company's interest rate derivative contracts are based on (i) the contracted notional amounts, (ii) forward active market-quoted London Interbank Offered Rates ("LIBOR") and (iii) the applicable credit-adjusted risk-free rate yield curve. The Company's interest rate derivative fair value measurements represent Level 2 inputs in the hierarchy.

Assets and liabilities measured at fair value on a nonrecurring basis. Certain assets and liabilities are measured at fair value on a nonrecurring basis. These assets and liabilities are not measured at fair value on an ongoing basis, but are subject to fair value adjustments in certain circumstances. These assets and liabilities can include inventory, proved and unproved oil and gas properties and other long-lived assets that are written down to fair value when they are impaired or held for sale. See Note C for information on the fair value of assets and liabilities acquired in the Permian Basin acquisition.The Company recognized noncash impairment charges of $6 million and $21 million for the nine months ended September 30, 2016 and 2015, respectively, attributable to inventory and other property and equipment.

Proved oil and gas properties. As a result of the Company's proved property impairment assessments, the Company recognized noncash impairment charges to reduce the carrying values of (i) the West Panhandle field during the three months ended March 31, 2016 and (ii) the Eagle Ford Shale field, the West Panhandle field and the South Texas - Other field during the year ended December 31, 2015 to their estimated fair values.

The Company calculated the fair values of the West Panhandle field, the Eagle Ford Shale field and the South Texas - Other field using a discounted future cash flow model. Significant Level 3 assumptions associated with the calculations included management's longer-term commodity price outlooks ("Management's Price Outlooks") and management's outlooks for (i) production costs, (ii) capital expenditures, (iii) production and (iv) estimated proved reserves and risk-adjusted probable reserves. Management's Price Outlooks are developed based on third-party longer-term commodity futures price outlooks as of each measurement date. The expected future net cash flows were discounted using an annual rate of 10 percent to determine estimated fair value.

The following table presents the fair value and fair value adjustments (in millions) for the Company's 2016 and 2015 proved property impairments, as well as the average oil price per barrel ("Bbl") and gas price per British thermal unit ("MMBtu") utilized in respective Management's Price Outlooks:



							Management's Price Outlooks
	Impairment Date	Fair Value		Fair Value Adjustment			Oil		Gas
West Panhandle	March 2016	$	33	$	(32	)	$	49.77	$	3.24
South Texas - Eagle Ford Shale	December 2015	$	483	$	(846	)	$	52.82	$	3.34
South Texas - Other	September 2015	$	88	$	(72	)	$	57.41	$	3.46
West Panhandle	March 2015	$	61	$	(138	)	$	65.02	$	3.83

It is reasonably possible that the estimate of undiscounted future net cash flows attributable to these or other properties may change in the future resulting in the need to impair their carrying values. The primary factors that may affect estimates of future cash flows are (i) future adjustments, both positive and negative, to proved and risk-adjusted probable and possible oil and gas reserves, (ii) results of future drilling activities, (iii) Management's Price Outlooks and (iv) increases or decreases in production and capital costs associated with these reserves.

Unproved oil and gas properties. During March 2016, the Company recorded an impairment charge of $32 million to write-off the carrying value of its unproved royalty acreage in Alaska (reported in exploration and abandonments in the accompanying consolidated statements of operations) as a result of the operator curtailing operations in the area and Management's Price Outlooks.

Financial instruments not carried at fair value. Carrying values and fair values of financial instruments that are not carried at fair value in the accompanying consolidated balance sheets as of September 30, 2016 and December 31, 2015 are as follows:



	September 30, 2016				December 31, 2015
	Carrying Value		Fair Value		Carrying Value		Fair Value
	(in millions)
Commercial paper, corporate bonds and time deposits	$	2,052	$	2,052	$	275	$	275
Current portion of long-term debt	$	485	$	496	$	448	$	462
Long-term debt	$	2,726	$	3,022	$	3,207	$	3,206

Commercial paper, corporate bonds and time deposits. Periodically, the Company invests in commercial paper and corporate bonds with investment grade rated entities. The Company also periodically enters into time deposits with financial institutions. The investments are carried at amortized cost, which approximates fair value, and classified as held-to-maturity as the Company has the intent and ability to hold them until they mature. The net carrying value of held-to-maturity investments is adjusted for amortization of premiums and accretion of discounts to maturity over the life of the investments. Income related to these investments is recorded in interest and other income in the Company's consolidated statement of operations. The investments represent Level 2 inputs in the hierarchy. Commercial paper, corporate bonds and time deposits are included in cash and cash equivalents if they have maturity dates that are less than 90 days at the date of purchase; otherwise, they are reflected in short-term investments or long-term investments in the accompanying consolidated balance sheets based on their maturity dates. The following table provides the components of the Company's cash and cash equivalents and investments as of September 30, 2016:



	September 30, 2016
Consolidated Balance Sheet Location	Cash		Commercial Paper		Corporate Bonds		Time Deposits		Total
	(in millions)
Cash and cash equivalents	$	891	$	—	$	—	$	—	$	891
Short-term investments	—		742		459		532		1,733
Long-term investments	—		—		319		—		319
	$	891	$	742	$	778	$	532	$	2,943

Debt obligations. Current and noncurrent long-term debt includes the Company's credit facility and the Company's senior notes. The fair value of the Company's debt obligations is determined utilizing inputs that are Level 2 measurements in the fair value hierarchy. The fair value of the Company's credit facility is calculated using a discounted cash flow model based on (i) forecasted contractual interest and fee payments, (ii) forward active market-quoted United States Treasury Bill rates and (iii) the applicable credit-adjustments. The Company's senior notes represent debt securities that are not actively traded on major exchanges. The fair values of the Company's senior notes are based on their periodic values as quoted on the major exchanges.

The Company has other financial instruments consisting primarily of receivables, prepaid expenses, payables and other current assets and liabilities that approximate fair value due to the nature of the instrument and their relatively short maturities. Non-financial assets and liabilities initially measured at fair value include assets acquired and liabilities assumed in a business combination, goodwill and asset retirement obligations.