Fair Value (Tables)

12 Months Ended

Dec. 31, 2013

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

Summary of financial instruments measured at fair value on a recurring basis

The following table presents the Company's financial instruments that were measured at fair value on a recurring basis at December 31, 2013 by level within the fair value hierarchy (in thousands):

	December 31, 2013
	Level 1		Level 2		Level 3		Total
Financial Assets
Money market funds	$	16,089	$	—	$	—	$	16,089
Corporate bonds	—		1,005		—		1,005
U.S. Treasury obligations	—		2,000		—		2,000
Common shares of CO2 Solutions			795		—		795
Total	$	16,089	$	3,800	$	—	$	19,889

The following table presents the Company's financial instruments that were measured at fair value on a recurring basis at December 31, 2012 by level within the fair value hierarchy (in thousands):

	December 31, 2012
	Level 1		Level 2		Level 3		Total
Financial Assets
Money market funds	$	24,789	$	—	$	—	$	24,789
Commercial paper	—		1,500		—		1,500
Corporate bonds	—		9,522		—		9,522
U.S. Treasury obligations	—		5,516		—		5,516
Common shares of CO2 Solutions	610		—		—		610
Total	$	25,399	$	16,538	$	—	$	41,937