INVESTMENTS

The Company invests part of its cash balances in a managed portfolio of liquid investments, including highly-rated corporate bonds, classified as short-term investments. The Company also invests in equity securities of silver and gold exploration and development companies. These investments are classified as available-for-sale and are measured at fair value in the financial statements with unrealized gains and losses recorded in Other comprehensive income (loss).



	At December 31, 2014
In thousands	Cost		Gross Unrealized Losses			Gross Unrealized Gains		Estimated Fair Value
Equity securities	$	5,687	$	(8	)	$	303	$	5,982



	At December 31, 2013
In thousands	Cost		Gross Unrealized Losses			Gross Unrealized Gains		Estimated Fair Value
Equity securities	$	17,649	$	(3,300	)	$	172	$	14,521

The following table summarizes the gross unrealized losses on investment securities for which other-than-temporary impairments have not been recognized and the fair values of those securities, aggregated by the length of time the individual securities have been in a continuous unrealized loss position, at December 31, 2014:



	Less than twelve months					Twelve months or more				Total
In thousands	Unrealized Losses			Fair Value		Unrealized Losses		Fair Value		Unrealized Losses			Fair Value
Equity securities	$	(8	)	$	38	$	—	$	—	$	(8	)	$	38

During 2014, the Company sold $49.1 million of short-term investments and $5.2 million of equity securities which resulted in the recognition of a realized loss of $0.6 million. The Company recognized net of tax unrealized losses of $2.3 million, $8.5 million, and $3.4 million in the years ended December 31, 2014, 2013, and 2012, respectively, in Other comprehensive income (loss). The Company performs a quarterly assessment on each of its equity securities with unrealized losses to determine if the security is other than temporarily impaired. The Company recorded other-than-temporary impairment losses of $6.6 million, $18.3 million and $0.6 million in the years ended December 31, 2014, 2013, and 2012, respectively.