Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2011


			Fair value measurements using:
	Fair Value		Level 1		Level 2		Level 3
December 31, 2011:
Cash and cash equivalents:
Money market funds	$	44,044	$	44,044		—		—
Short-term investments:
U.S. Treasury bills	$	74,996	$	74,996		—		—

December 31, 2010:
Cash and cash equivalents:
Money market funds	$	53,657	$	53,657		—		—
Short-term investments:
U.S. Treasury note	$	99,964	$	99,964		—		—

- Definition

Tabular disclosure of assets, including [financial] instruments measured at fair value that are classified in stockholders' equity, if any, by class that are measured at fair value on a recurring basis. The disclosures contemplated herein include the fair value measurements at the reporting date by the level within the fair value hierarchy in which the fair value measurements in their entirety fall, segregating fair value measurements using quoted prices in active markets for identical assets (Level 1), significant other observable inputs (Level 2), and significant unobservable inputs (Level 3).

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