Investments

We hold investments in certain publicly traded companies and privately held entities involved primarily in the science industry. Our investments in privately held entities are primarily accounted for under the cost method. Our investments in publicly traded companies are principally marketable equity securities which are accounted for as “available for sale” securities that are carried at their fair values. Investments in “available for sale” securities with gross unrealized losses as of March 31, 2015, had been in a continuous unrealized loss position for less than 12 months. We have the ability and intent to hold these investments for a reasonable period of time sufficient for the recovery of our investment. We believe that these unrealized losses are temporary and accordingly there are no other-than-temporary impairments in accumulated other comprehensive income related to “available for sale” securities as of March 31, 2015, or December 31, 2014.

The following table summarizes our investments as of March 31, 2015, and December 31, 2014 (in thousands):



	March 31, 2015			December 31, 2014
“Available-for-sale” marketable equity securities, cost basis	$	33,851		$	21,898
Unrealized gains	83,513			53,625
Unrealized losses	(1,608		)	(1,258		)
“Available-for-sale” marketable equity securities, at fair value	115,756			74,265
Investments accounted for under cost method	167,306			162,124
Total investments	$	283,062		$	236,389

The following table outlines our investment income, which is classified in other income in the accompanying consolidated statements of income (in thousands):



	Three Months Ended March 31,
	2015			2014
Investment gains	$	5,937		$	4,040
Investment losses	(2,225		)	(1,694		)
Investment income	$	3,712		$	2,346