Fair Value Measurements

3 Months Ended

Mar. 31, 2013

Fair Value Disclosures [Abstract]

Fair Value Measurements

FAIR VALUE MEASUREMENTS

Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants. A three-level fair value hierarchy prioritizes the inputs used to measure fair value. This hierarchy requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The classification of each financial asset or liability within the hierarchy is determined based on the lowest level input that is significant to the fair value measurement. The three levels of inputs used to measure fair value are as follows:

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

• Level 2 - Observable inputs other than quoted prices included in Level 1 such as quoted prices for similar assets and liabilities in active markets; quoted prices for identical or similar assets and liabilities in markets that are not active; or inputs that are observable or can be corroborated by observable market data.

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

Financial assets and liabilities measured at fair value on a recurring basis at March 31, 2013 and December 31, 2012, consisted of the following:

(In thousands)	Fair Value Measurements
At March 31, 2013	Total		Level 1		Level 2		Level 3
Mutual funds	$	1,708	$	1,708	$	—	$	—
Investments
Federal agency notes	$	113,818	$	—	$	113,818	$	—
Commercial paper	$	145,196	$	—	$	145,196	$	—

(In thousands)	Fair Value Measurements
At December 31, 2012	Total		Level 1		Level 2		Level 3
Mutual funds	$	1,817	$	1,817	$	—	$	—
Investments
Federal agency notes	$	124,715	$	—	$	124,715	$	—
Commercial paper	$	137,268	$	—	$	137,268	$	—

The fair value of mutual funds and investments is based on market prices which are readily available. Unrealized gains or losses on mutual funds and investments are recorded in Accumulated other comprehensive loss on the Company's Consolidated Balance Sheets.

Financial assets and liabilities measured at fair value on a nonrecurring basis at March 31, 2013 and December 31, 2012, consisted of the following:

(In thousands)	Fair Value Measurements
At March 31, 2013	Total		Level 1		Level 2		Level 3
1.875% Convertible debentures	$	2,245	$	—	$	2,245	$	—
1.75% Convertible debentures	$	311,692	$	—	$	311,692	$	—
Exempt facility revenue bonds	$	32,329	$	—	$	—	$	32,329

(In thousands)	Fair Value Measurements
At December 31, 2012	Total		Level 1		Level 2		Level 3
1.875% Convertible debentures	$	166,292	$	—	$	166,292	$	—
1.75% Convertible debentures	$	302,466	$	—	$	302,466	$	—
Exempt facility revenue bonds	$	29,968	$	—	$	—	$	29,968

The Company used implicit interest rates of comparable unsecured obligations to calculate the fair value of the Company’s $30 million8% Series 2000 exempt facility industrial revenue bonds at March 31, 2013, and December 31, 2012. The Company used its current trading data to determine the fair value of each of its convertible debentures, the $2.2 million, 1.875% convertible debentures and the $396.75 million, 1.75% convertible debentures at March 31, 2013 and December 31, 2012. The fair value of the Company's long-term investments in certain Canadian exploration companies at March 31, 2013 and December 31, 2012 is based on market prices which are readily available.