Derivative Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2018

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Derivative instruments, future settlement

At March 31, 2018, the Company had the following derivative instruments that settle as follows:

In thousands except average prices and notional ounces	2018			Thereafter
Provisional silver sales contracts	$	831		$	—
Average silver price per ounce	$	16.66		$	—
Notional ounces	49,853			—
Provisional gold sales contracts	$	59,332		$	—
Average gold price per ounce	$	1,317		$	—
Notional ounces	45,051			—
Zinc put options purchased	$	8,100		$	—
Average zinc strike price per metric ton	$	3,000		$	—
Notional metric tons	2,700			—
Zinc call options sold	$	(10,935	)	$	—
Average zinc strike price per metric ton	$	4,050		$	—
Notional metric tons	2,700			—

Fair value of the derivative instruments

The following summarizes the classification of the fair value of the derivative instruments:

	March 31, 2018
In thousands	Prepaid expenses and other		Accrued liabilities and other		Current portion of royalty obligation		Non-current portion of royalty obligation
Provisional silver and gold sales contracts	$	407	$	125	$	—	$	—
Zinc options	145		—		—		—
	$	552	$	125	$	—	$	—

	December 31, 2017
In thousands	Prepaid expenses and other		Accrued liabilities and other		Current portion of royalty obligation		Non-current portion of royalty obligation
Provisional silver and gold sales contracts	$	251	$	222	$	—	$	—

Gain losses on derivative instruments

The following represent mark-to-market gains (losses) on derivative instruments for the three months ended March 31, 2018 and 2017, respectively (in thousands):

		Three months ended March 31,
Financial statement line	Derivative	2018		2017
Revenue	Provisional silver and gold sales contracts	$	253	$	1,212
Fair value adjustments, net	Zinc options	145		—
		$	398	$	1,212