Derivative Financial Instruments - Summary of Provisionally Priced Sales (Details) $ in Thousands	Dec. 31, 2019 USD ($) oz $ / oz
Silver concentrate sales agreements | 2018
Derivative instruments Settlement
Derivative, notional amount	$ (8,116)
Derivative average price | $ / oz	17.89
Outstanding Provisionally Priced Sales Consists of Silver | oz	453,610
Silver concentrate sales agreements | Thereafter
Derivative instruments Settlement
Derivative, notional amount	$ 0
Derivative average price | $ / oz	0
Outstanding Provisionally Priced Sales Consists of Silver | oz	0
Gold concentrates sales agreements | 2018
Derivative instruments Settlement
Derivative, notional amount	$ (16,265)
Derivative average price | $ / oz	1,471
Outstanding Provisionally Priced Sales Consists of Gold | oz	11,054
Gold concentrates sales agreements | Thereafter
Derivative instruments Settlement
Derivative, notional amount	$ 0
Derivative average price | $ / oz	0
Outstanding Provisionally Priced Sales Consists of Gold | oz	0
Zinc concentrates sales agreements [Member] | 2018
Derivative instruments Settlement
Derivative, notional amount	$ (10,762)
Derivative average price | $ / oz	1.03
Outstanding Provisionally Priced Sales Consists of Gold | oz	10,411,742
Zinc concentrates sales agreements [Member] | Thereafter
Derivative instruments Settlement
Derivative, notional amount	$ 0
Derivative average price | $ / oz	0
Outstanding Provisionally Priced Sales Consists of Gold | oz	0
Lead concentrates sales agreements [Member] | 2018
Derivative instruments Settlement
Derivative, notional amount	$ (5,485)
Derivative average price | $ / oz	0.88
Outstanding Provisionally Priced Sales Consists of Gold | oz	6,205,968
Lead concentrates sales agreements [Member] | Thereafter
Derivative instruments Settlement
Derivative, notional amount	$ 0
Derivative average price | $ / oz	0
Outstanding Provisionally Priced Sales Consists of Gold | oz	0
Fixed Interest Rate Swap One
Derivative instruments Settlement
Derivative, notional amount	$ (50,000)
Fixed Interest Rate Swap Two
Derivative instruments Settlement
Derivative, notional amount	$ (75,000)