Marketable Securities

6 Months Ended

Jun. 30, 2017

Investments, Debt and Equity Securities [Abstract]

All of our marketable securities are classified as available-for-sale and consist of United States Treasury notes, which mature in 2019, and common stock. Available-for-sale securities are presented on our condensed consolidated balance sheets at fair value. Changes in values of these securities are recognized in accumulated other comprehensive income (loss). Realized gains and losses are recognized in earnings only upon the sale of the securities.

We evaluate our marketable securities for impairment each reporting period. For securities with unrealized losses, we review the underlying cause of the decline in value and the estimated recovery period, as well as the severity and duration of the decline. In our evaluation, we consider our ability and intent to hold these investments for a reasonable period of time sufficient for us to recover our cost basis. To the extent an other-than-temporary impairment is deemed to have occurred, an impairment charge is recorded and a new cost basis is established.

Below is a summary of our marketable securities as of June 30, 2017 (in thousands):



	June 30, 2017
	Cost or Amortized Cost		Unrealized Gains		Estimated Fair Value
Marketable securities	$	276,368	$	1,704	$	278,072