Fair Value Measurements

3 Months Ended

Mar. 31, 2012

Fair Value Disclosures [Abstract]

Fair Value Measurements

6. FAIR VALUE MEASUREMENTS

The authoritative guidance defines fair value as an exit price, representing the amount that would either be received to sell an asset or be paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows:

• Level 1. Observable inputs such as quoted prices in active markets for identical assets or liabilities;

• Level 2. Inputs, other than the quoted prices in active markets, that are observable either directly or indirectly; and

• Level 3. Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions.

Available-for-sale securities included in Level 2 are valued utilizing inputs obtained from an independent pricing service (the “Service”) which uses quoted market prices for identical or comparable instruments rather than direct observations of quoted prices in active markets. The Service gathers observable inputs for all of the Company’s fixed income securities from a variety of industry data providers including, for example, large custodial institutions and other third-party sources. Once the observable inputs are gathered by the Service, all data points are considered and an average price is determined. The Service’s providers utilize a variety of inputs to determine their quoted prices. These inputs may include interest rates, known historical trades, yield curve information, benchmark data, prepayment speeds, credit quality and broker/dealer quotes. Substantially all of the Company’s available-for-sale investments are valued utilizing inputs obtained from the Service and accordingly are categorized as Level 2 in the table below. The Company periodically independently assesses the pricing obtained from the Service and historically has not adjusted the Service's pricing as a result of this assessment. Available-for-sale securities are included in Level 3 when relevant observable inputs for a security are not available.

The Company’s assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the classification of assets and liabilities within the fair value hierarchy. In certain instances, the inputs used to measure fair value may meet the definition of more than one level of the fair value hierarchy. The input with the lowest level priority is used to determine the applicable level in the fair value hierarchy.

Assets and Liabilities Measured at Fair Value on a Recurring Basis

	As of March 31, 2012		Quoted Prices In Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
	(in thousands)
Assets:
Cash and cash equivalents:
Money market funds	$	136,453	$	136,453	$	—	$	—
Corporate securities	51,168		—		51,168		—
Municipal securities	6,029		—		6,029		—
Cash	197,231		197,231		—		—
Available-for-sale securities:
Agency securities	661,303		—		661,303		—
Corporate securities	459,084		—		454,278		4,806
Municipal securities	69,978		—		69,978		—
Government securities	27,454		—		27,454		—
Prepaid expenses and other current assets:
Foreign currency derivatives	3,387		—		3,387		—
Total assets	$	1,612,087	$	333,684	$	1,273,597	$	4,806
Accrued expenses and other current liabilities:
Foreign currency derivatives	5,083		—		5,083		—
Total liabilities	$	5,083	$	—	$	5,083	$	—

The Company’s fixed income available-for-sale security portfolio generally consists of high quality, investment grade securities from diverse issuers with a minimum credit rating of A-/A3 and a weighted average credit rating of AA+/Aa1. The Company values these securities based on pricing from the Service, whose sources may use quoted prices in active markets for identical assets (Level 1 inputs) or inputs other than quoted prices that are observable either directly or indirectly (Level 2 inputs) in determining fair value, the Company classifies all of its fixed income available-for-sale securities as Level 2. See Note 5 for more information regarding the Company’s available-for-sale investments.

The Company measures its cash flow hedges, which are classified as Prepaid expenses and other current assets and Accrued expenses and other current liabilities, at fair value based on indicative prices in active markets (Level 2 inputs).

The Company has invested in convertible debt securities of certain early-stage entities that are classified as available-for-sale investments. As quoted prices in active markets or other observable inputs were not available for these investments, in order to measure them at fair value, the Company utilized a discounted cash flow model using a discount rate reflecting the market risk inherent in holding securities of an early-stage enterprise, adjusted by the probability-weighted exit possibilities associated with the convertible debt securities. Typically the discount rate used by the Company in measuring the fair value of investments in convertible debt securities of certain early-stage entities is commensurate with the nature and size of these entities. This methodology required the Company to make assumptions that were not directly or indirectly observable regarding the fair value of the convertible debt securities; accordingly it is a Level 3 valuation and is included in the table below.

Assets Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Level 3)

	Investments
	(in thousands)
Balance at December 31, 2011	$	3,696
Purchases of Level 3 securities	1,252
Transfers out of Level 3	(142		)
Balance at March 31, 2012	$	4,806

Additional Disclosures Regarding Fair Value Measurements

The carrying value of accounts receivable, accounts payable and accrued expenses approximate their fair value due to the short maturity of these items.