Fair Value Measurements - Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Assets:
Equity securities	$ 9,293	$ 132,197
Fair Value, Recurring
Assets:
Assets	92,741	132,283
Liabilities:
Total liabilities		1,374
Provisional metal sales contracts | Fair Value, Recurring
Assets:
Fair value of other derivative instruments, net	120	86
Liabilities:
Fair value of derivative liability	948	162
Gold zero cost collars | Fair Value, Recurring
Liabilities:
Fair value of derivative liability		1,212
Gold Forwards | Fair Value, Recurring
Assets:
Fair value of other derivative instruments, net	47,073
Equity Securities | Fair Value, Recurring
Assets:
Equity securities		132,197
Liabilities:
Marketable securities including warrants	45,548
Level 1 | Fair Value, Recurring
Assets:
Assets	45,435	132,197
Liabilities:
Total liabilities		0
Level 1 | Provisional metal sales contracts | Fair Value, Recurring
Assets:
Fair value of other derivative instruments, net	0	0
Liabilities:
Fair value of derivative liability	0	0
Level 1 | Gold zero cost collars | Fair Value, Recurring
Liabilities:
Fair value of derivative liability		0
Level 1 | Gold Forwards | Fair Value, Recurring
Assets:
Fair value of other derivative instruments, net	0
Level 1 | Equity Securities | Fair Value, Recurring
Assets:
Equity securities		132,197
Liabilities:
Marketable securities including warrants	45,435
Level 2 | Fair Value, Recurring
Assets:
Assets	47,306	86
Liabilities:
Total liabilities		1,374
Level 2 | Provisional metal sales contracts | Fair Value, Recurring
Assets:
Fair value of other derivative instruments, net	120	86
Liabilities:
Fair value of derivative liability	948	162
Level 2 | Gold zero cost collars | Fair Value, Recurring
Liabilities:
Fair value of derivative liability		1,212
Level 2 | Gold Forwards | Fair Value, Recurring
Assets:
Fair value of other derivative instruments, net	47,073
Level 2 | Equity Securities | Fair Value, Recurring
Assets:
Equity securities		0
Liabilities:
Marketable securities including warrants	113
Level 3   | Fair Value, Recurring
Assets:
Assets	0	0
Liabilities:
Total liabilities		0
Level 3   | Provisional metal sales contracts | Fair Value, Recurring
Assets:
Fair value of other derivative instruments, net	0	0
Liabilities:
Fair value of derivative liability	0	0
Level 3   | Gold zero cost collars | Fair Value, Recurring
Liabilities:
Fair value of derivative liability		0
Level 3   | Gold Forwards | Fair Value, Recurring
Assets:
Fair value of other derivative instruments, net	0
Level 3   | Equity Securities | Fair Value, Recurring
Assets:
Equity securities		$ 0
Liabilities:
Marketable securities including warrants	$ 0