Fair Value Measurements

6 Months Ended

Jun. 30, 2011

Fair Value Measurements [Abstract]

Fair Value Measurements

7. Fair Value Measurements

Accounting standards require that assets and liabilities carried at fair value will be classified and disclosed in one of the following three categories:

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

Level 2: Observable market based inputs or unobservable inputs that are corroborated by market data.

Level 3: Unobservable inputs that are not corroborated by market data.

The following table summarizes the valuation of our short-term investments and financial instruments by the above pricing levels as of the valuation dates listed:

			June 30, 2011
	Total		(Level 1)		(Level 2)
	(Thousands of dollars)
Short-term investments:
Money Market Mutual Funds	$	38,941	$	38,941	$	—
Commercial Paper		12,997		—		12,997
Corporate bonds and notes		37,812		—		37,812
		89,750		38,941		50,809
Investments in other assets		2,868		2,868		—
Total	$	92,618	$	41,809	$	50,809

			December 31, 2010
	Total		(Level 1)		(Level 2)
	(Thousands of dollars)
Short-term investments:
Money Market Mutual Funds	$	33,968	$	33,968	$	—
Commercial Paper		42,455		—		42,455
U.S. Government Agencies		8,013		—		8,013
Corporate bonds and notes		65,636		—		65,636
		150,072		33,968		116,104
Investments in other assets		3,547		3,547		—
Total	$	153,619	$	37,515	$	116,104

The Company holds its short-term investments in an investment fund consisting of high quality money market instruments of governmental and private issuers, which is classified as short-term investments.

Level 1 inputs are quoted prices (unadjusted) for identical assets or liabilities in active markets. These items are traded with sufficient frequency and volume to provide pricing on an ongoing basis. The fair values of the shares of these funds are based on observable market prices, and therefore, have been categorized in Level 1 in the fair value hierarchy. Level 2 inputs reflect quoted prices for identical assets or liabilities that are not active. These items may not be traded daily; examples include corporate bonds and U.S. government agencies. Assets are valued based on prices derived by independent third parties that use inputs such as benchmark yields, reported trades, broker/dealer quotes, and issuer spreads. Prices are reviewed and can be challenged with the independent parties and/or overridden by the Company, if it is believed such would be more reflective of fair value. Investments included in other assets, which relate to the liability for the Officers’ Deferred Compensation Plan, consist mainly of multiple investment funds that are highly liquid and diversified.

Cash, accounts receivable, accounts payable and accrued liabilities all had fair values approximating their carrying amounts at June 30, 2011 and December 31, 2010.