Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2012

Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]

Assets and Liabilities Measured at Fair Value on Recurring Basis

The following table presents our fair value hierarchy for our assets and liabilities measured at fair value on a recurring basis at December 31, 2012 (in thousands):

	Level 1		Level 2		Level 3		Total
Cash equivalents:
Money market funds	$	35,429	$	—	$	—	$	35,429
Commercial paper	—		36,082		—		36,082
Short-term investments:
Commercial paper	—		36,753		—		36,753
Corporate notes and bonds	—		157,948		—		157,948
U.S. government agency securities	—		1,001		—		1,001
Total	$	35,429	$	231,784	$	—	$	267,213

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation

Level 3 activity is as follows (in thousands):

	Level 3
Balance at June 30, 2009	$	128
Interest and other income (expense), net for change in fair value of preferred stock warrants	702
Net settlement of preferred stock warrant liability	(830		)
Balance at June 30, 2010	$	—