Marketable Securities (Tables)

3 Months Ended

Mar. 31, 2016

Cash Equivalents and Marketable Securities [Abstract]

Schedule of cash equivalents and marketable securities

t March 31, 2016 and at December 31, 2015 consisted of the following (in thousands):

	March 31, 2016
	Adjusted Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value		Average Contractual Maturities
									(in days)
Money market funds (1)	$	11,130	$	—	$	—	$	11,130	n/a
Common shares of CO2 Solutions (2)	563		896		—		1,459		n/a
Total	$	11,693	$	896	$	—	$	12,589

	December 31, 2015
	Adjusted Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value		Average Contractual Maturities
									(in days)
Money market funds (1)	$	11,120	$	—	$	—	$	11,120	n/a
Common shares of CO2 Solutions (2)	563		986		—		1,549		n/a
Total	$	11,683	$	986	$	—	$	12,669

(1) Money market funds are classified in cash and cash equivalents on our condensed consolidated balance sheets.

(2) Common shares of CO2 Solutions are classified in marketable securities on our condensed consolidated balance sheets.