Fair Value Measurement of Financial Assets and Liabilities. We apply fair value accounting for all financial assets and liabilities and non-financial assets and liabilities that are recognized or disclosed at fair value in the financial statements on a recurring basis. We define fair value as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities that are required to be recorded at fair value, we consider the principal or most advantageous market in which we would transact and the market-based risk measurements or assumptions that market participants would use in pricing the asset or liability, such as inherent risk, transfer restrictions and credit risk.

GAAP establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring the fair values of financial and non-financial assets and liabilities. These tiers consist of:

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 tables summarize the fair value measurements (in thousands of dollars) of our financial assets and liabilities:


	At June 30, 2012
	Total		Quoted market prices in active markets (level 1)		Significant other observable inputs (Level 2)
Cash Equivalents—Overnight Investments	$	1,593	$	—	$	1,593

	At December 31, 2011
	Total		Quoted market prices in active markets (level 1)		Significant other observable inputs (Level 2)
Cash Equivalents—Overnight Investments	$	3,190	$	—	$	3,190

The Company had no level 3 assets or liabilities at June 30, 2012 and December 31, 2011.

We use the income approach to value derivatives, using observable Level 2 market expectations at measurement date and standard valuation techniques to convert future amounts to a single discounted present amount, assuming that participants are motivated but not compelled to transact. Level 2 inputs are limited to quoted prices that are observable for the asset and liabilities, which include interest rate and credit risk. We have used mid market pricing as a practical expedient for fair value measurements.