Fair Value Measurements

3 Months Ended

Mar. 31, 2012

Fair Value Measurements [Abstract]

Fair Value Measurements

3. Fair Value Measurements

The Company categorizes its assets and liabilities measured at fair value into a fair value hierarchy that prioritizes the inputs used in pricing the asset or liability. The three levels of the fair value hierarchy are:

• Level 1: Observable inputs such as quoted prices for identical assets and liabilities in active markets obtained from independent sources.

• Level 2: Other inputs that are observable directly or indirectly, such as 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 and inputs that are derived principally from or corroborated by observable market data. The fair value of the Company's level 2 financial assets is primarily obtained from observable market prices for identical underlying securities that may not be actively traded. Certain of these securities may have different market prices from multiple market data sources, in which case a weighted average market price is used.

• Level 3: Unobservable inputs for which there is little or no market data and require the Company to develop its own assumptions, based on the best information available in the circumstances, about the assumptions market participants would use in pricing the asset or liability.

The following tables present the Company's assets that are measured at fair value on a recurring basis:

	March 31, 2012
(in thousands)	Quoted Market Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total Fair Value Measurements
Short-term investments:
U.S. government and agency securities	$	—	$	4,915	$	—	$	4,915
Corporate obligations		—		20,783		—		20,783
Other fixed income securities		—		543		—		543
International securities	$	—		9,859	$	—		9,859
Total	$	—	$	36,100	$	—	$	36,100

	December 31, 2011
(in thousands)	Quoted Market Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total Fair Value Measurements
Short-term investments:
U.S. government and agency securities	$	—	$	3,858	$	—	$	3,858
Corporate obligations		—		5,122		—		5,122
Other fixed income securities		—		545		—		545
International securities	$	—		1,526	$	—		1,526
Total	$	—	$	11,051	$	—	$	11,051

The Company has no liabilities that are measured at fair value on a recurring basis.

Assets measured at fair value on a nonrecurring basis

The Company's non-financial assets, such as goodwill, intangible assets and property and equipment, are measured at fair value when there is an indicator of impairment and are recorded at fair value only when an impairment charge is recognized. Such impairment charges incorporate fair value measurements based on level 3 inputs.