Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2015

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

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

The following table presents the financial instruments that were measured at fair value on a recurring basis at March 31, 2015 by level within the fair value hierarchy (in thousands):

	March 31, 2015
	Level 1		Level 2		Level 3		Total
Money market funds	$	14,603	$	—	$	—	$	14,603
Common shares of CO2 Solutions	—		712		—		712
Total	$	14,603	$	712	$	—	$	15,315

The following table presents the financial instruments that were measured at fair value on a recurring basis at December 31, 2014 by level within the fair value hierarchy (in thousands):

	December 31, 2014
	Level 1		Level 2		Level 3		Total
Money market funds	$	14,602	$	—	$	—	$	14,602
Common shares of CO2 Solutions	—		688		—		688
Total	$	14,602	$	688	$	—	$	15,290