INVESTMENTS

Equity and Debt Securities

The Company makes strategic investments in equity and debt securities of silver and gold exploration and development companies.



	At September 30, 2018
In thousands	Cost		Gross Unrealized Losses			Gross Unrealized Gains		Estimated Fair Value
Equity Securities
Metalla Royalty & Streaming Ltd.	8,147		—			2,113		10,260
Northern Empire Resources Corp. ⁽¹⁾	4,489		—			2,716		7,205
Rockhaven Resources, Ltd.	2,064		(538		)	—		1,526
Other	1,390		(716		)	—		674
Equity securities	$	16,090	$	(1,254	)	$	4,829	$	19,665

Debt Securities
Metalla Royalty & Streaming Ltd.	$	4,825	$	(258	)	$	—	$	4,567

Equity and debt securities	$	20,915	$	(1,512	)	$	4,829	$	24,232

(1) In October 2018, the Company acquired the remaining outstanding shares of Norther Empire Resources Corp. not already owned by the Company. See Note 23 -- Subsequent Events for additional detail.



	At December 31, 2017
In thousands	Cost		Gross Unrealized Losses			Gross Unrealized Gains		Estimated Fair Value
Equity Securities
Metalla Royalty & Streaming Ltd.	$	6,294	$	—		$	1,354	$	7,648
Corvus Gold Inc.	3,582		—			4,518		8,100
Almaden Minerals, Ltd.	3,125		(235		)	—		2,890
Northern Empire Resources Corp.	4,489		—			1,077		5,566
Rockhaven Resources, Ltd.	2,064		(193		)	—		1,871
Kootenay Silver, Inc.	738		—			1		739
Other	1,479		(453		)	405		1,431
Equity securities	$	21,771	$	(881	)	$	7,355	$	28,245

Debt Securities
Metalla Royalty & Streaming Ltd.	$	6,677	$	(85	)	$	—	$	6,592

Equity and debt securities	$	28,448	$	(966	)	$	7,355	$	34,837

The following table presents the disaggregated gain (loss) on equity securities recognized in Income (loss) from continuing operations on the Condensed Consolidated Statements of Comprehensive Income:



	Three months ended September 30,					Nine months ended September 30,
In thousands	2018		2017			2018			2017
Net gain (loss)	$	283	$	(32	)	$	2,301		$	(1,300	)
Less: Realized (gain) loss	3		32			(5,199		)	1,300
Unrealized gain (loss)	$	286	$	—		$	(2,898	)	$	—

The Company performs a quarterly assessment on its debt securities with unrealized losses to determine if the securities are other than temporarily impaired. The following table summarizes unrealized losses on debt 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 September 30, 2018:

Less than twelve months

Twelve months or more

Total

In thousands

Unrealized Losses

Fair Value

Unrealized Losses

Fair Value

Unrealized Losses

Fair Value

Debt securities

—

257

4,568

257

4,568

Restricted Assets

The Company, under the terms of its self-insurance and bonding agreements with certain banks, lending institutions and regulatory agencies, is required to collateralize certain portions of its asset retirement obligations. The Company has collateralized these obligations by assigning certificates of deposit that have maturity dates ranging from three months to a year to the applicable institutions or agencies. At September 30, 2018 and December 31, 2017, the Company held certificates of deposit and cash equivalents under these agreements of $21.4 million and $20.8 million, respectively. The ultimate timing of the release of the collateralized amounts is dependent on the timing and closure of each mine and repayment of the obligation. In order to release the collateral, the Company must seek approval from certain government agencies responsible for monitoring the mine closure status. Collateral could also be released to the extent the Company is able to secure alternative financial assurance satisfactory to the regulatory agencies. The Company believes the collateral will remain in place beyond a twelve-month period and has therefore classified these investments as long-term.