Marketable Securities (Tables)

9 Months Ended

Sep. 30, 2015

Cash Equivalents and Marketable Securities [Abstract]

Schedule of cash equivalents and marketable securities

At September 30, 2015, securities classified as available-for-sale consisted of the following (in thousands):

	September 30, 2015
	Adjusted Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value		Average Contractual Maturities
									(in days)
Money market funds (1)	$	11,115	$	—	$	—	$	11,115	n/a
Common shares of CO2 Solutions (2)	563		668		—		1,231		n/a
Total	$	11,678	$	668	$	—	$	12,346

(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 as marketable securities on our condensed consolidated balance sheets.

There were no marketable securities in an unrealized loss position at September 30, 2015.

At December 31, 2014, securities classified as available-for-sale consisted of the following (in thousands):

	December 31, 2014
	Adjusted Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value		Average Contractual Maturities
									(in days)
Money market funds (1)	$	14,602	$	—	$	—	$	14,602	n/a
Common shares of CO2 Solutions (2)	563		125		—		688		n/a
Total	$	15,165	$	125	$	—	$	15,290

(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.